Antennas For TV, CB, FM, Shortwave

Collection

Survival, Water, Medical Field Manuals

Case

Military Manuals

Sub-case

Swan, Franklin E.

Download PDF ↗ Live URL (may be dead)

Document text

for N ЫН Ри.
Shortwave

HOW TO SELECT AND „У Ly |
INSTALL THEN. Уу 22°

ANTENNAS FOR TV, CB, FM,
SHORTWAVE—
How To Select And Install Them

by
Franklin E. Swan

A Revision of
ANTENNAS FOR TV, CB, SHORTWAVE

by Louis M. Dezettel

Radie Shaek

ҢА TANDY CORPORATION COMPANY

THIRD EDITION
FIRST PRINTING -1983

United States of America.

All rights reserved. Reproduction or use, without express permis-
Sion, of editorial or pictorial content, in any manner, is prohibited.
No patent liability is assumed with respect to the use of the
information contained herein.

Library of Congress Catalog Card Number: 83-61433

PREFACE

Modern electronics has resulted in a considerable improvement in
the performance of color TV sets, Citizens band equipment and other
equipment using antennas to receive a signal One thing even
sophisticated circuitry can't seem to affect is the action of the radio
waves coming to the set. Whatever control we have external to the
set takes the form of an antenna.

This book is a revision of Antennas for TV, CB, Shortwave which
was a revision of Introduction to Antennas by Louis M. Dezettel.
This need for constant up-dating is a reflection of both the improve-
ment in equipment and changes in laws controlling the manufacture
and installation of antenna systems. This latest revision includes the
laws going into affect by mid 1983.

With the considerable dollar investment in a good color TV set, CB
transceiver, shortwave radio, or FM hi-fi equipment, it becomes
important to give thought to the selection of the antenna and, just as
important, its installation. You can enhance the performance of your
investment by spending a few minutes reading this book and
following its suggestion. It can make the difference between passable
performance and very good performance.

Along with many others I would like to thank Mr. Dezettel for his
many years of technical writing, and wish him well in his retirement.

FRANKLIN E. SWAN

CONTENTS

CHAPTER 1

LEE TCU — €
A Word About Resonance—Broadband Antennas-— Direct and Reflected

Waves—Multipath Signals

CHAPTER 2

DV ASTENNASL cierre КОЛКОГО ООС Rs
VHF and UHF Antennas—Color TV Antennas

CHAPTER 3

SELECTING THE Proper TV ANTENNA... ә... eere нинен икен кенен кекене,
To Eliminate Ghosts—Choosing the Antenna—TV for Recreational Vehicles

CHAPTER 4

SPECIAL ANTENNAS FOR FM........... eee —
The Resonant Antenna—Unidirectional and Omnidirectional Antennas

Stereo Reception and Antennas

CHAPTER 5

FniNGE AREA TV/FM АХтЕК+хАЗ................... “КУО СОЛ УЫ
Distance and Signal Strength—Long-Range Antennas Need for Height—

Masts and Towers

CHAPTER 6

MULTIPLE-SET DISTRIBUTION.............. cesses eene enne enn 37
Impedance Matching—Amplified Systems—Interconnecting Cable

CHAPTER 7

How To INSTALL A ТУ АмтЕММА............... оаа 47
Roof Mounting—Chimney Mounting—Wall Mounting—Mast Mounting—
Running the Lead-In—Standoffs—Running Lead-In Indoors—Wall Mount-
ing Sockets

CHAPTER 8
IupooR. TV JANTENNAS.....«:. 6925 eoe sene e ey SER S eisiaa жее 61
Design for Today's TV—The Finest Indoor TV Antenna—FM Indoor
Antennas
CHAPTER 9
INSTALLING A: ROTATOR... 8 eres eese ы ведена аа SWR EE NUEVA ERE EVE 71

Manual and Automatic Rotators—Running the Control Cable—Orientating
for Direction

CHAPTER 10

TV INTERFERENCE AND Wuar To Do ABOUT 1т............................ 15
Snow—Ghosts—Interference Filters—Sparking—The Herringbone Pat-
tern—Picture Flutter

CHAPTER 11

CB ANTENNAS.......... eene ТЯ UT tr
Antenna Lengths and Impedance Matching — -Quastar Wave Ground-Plane
Antenna— Half-Wave Ground-Plane Antenna—%-Wave and .64-Wave
Antennas—Coaxial Antenna—Indoor CB Antenna—Beam Antenna—
Cubical Quad Antennas—Mobile Antennas—CB/FM/AM Disguise Anten-
nas— Laws Affecting CB Antennas

CHAPTER 12

INSTALLING FIXED-STATION CB ANTENNAs......... eene 96
Height—Home Roof Mounting—Connecting the Feedline—Grounding for
Protection—Installing Coaxial Cable Connectors

CHAPTER 13

INSTALLING THE MOBILE АМТЕММА............ —€——— P
Trunk Lid Mount—Gutter-Mount Antenna—Bumper-Mount Antenna—
Connecting The Cable—Tuning the Antenna—Useful Accessories—Noise
Filters

CHAPTER 14

ANTENNAS FOR SHORTWAVE LISTENERS............« e
The Inverted “L” Universal Antenna— Packaged Complete Antennas—The
Half-Wave Folded-Dipole Antenna—Supporting the Antenna—Bringing in
the Lead-In—Connecting to the Receiver

CHAPTER 15

Important Safety Rules—Cutting Into a Wall—Roof Safety—Lightning
Protection—Soil Effectiveness

CHAPTER 1

WHAT ANTENNAS DO

Thousands of watts of radio-wave power, transmitted from a TV or
other transmitting antenna, are radiated outward. By the time they
get to your receiving antenna very little is left. The amount of power
your TV antenna actually feeds to your set may be on the order oftwo
or three hundred microwatts (millionths of a watt). It is for this
reason that it is important to use a highly efficient antenna, especially
if there is any appreciable distance between the transmitter and the
receiver.

For the mathematically minded, the loss of power is the same as for
light—the inverse-square law applies. That is, the loss is in inverse
proportion to the square of the distance (Figure 1-1). The light
passing through a 1-sq ft window at a distance of one foot would cover
a4-sq ft area at two feet. The intensity of the light at a single point at
a distance of two feet is one-fourth that at one foot. This is the
inverse-square law, and it applies as well to the decrease in power ofa
radio wave as it travels away from a transmitter.

SOURCE

4SQ FT

Figure 1-1. The inverse-square law.

A WORD ABOUT RESONANCE

Piano strings are different in length, and when struck by the
hammer will vibrate at specific musical frequencies. The longer
strings (or wires) vibrate at low frequencies and the shorter ones at
higher frequencies. The length and tautness of the piano strings
determine their resonant frequency, or frequency of natural
vibration, This is mechanical resonance. Ер

Transmitters and receivers contain resonant circuits within them.
When you switch channels in a TV set, you are switching to different
resonant circuits. This not only makes the set selective to only the
one channel, but increases the sensitivity to that channel. The
resonant circuits are in the form of small coils and capacitors, and are
called “lumped” resonant circuits.

When a length of wire is cut to a specific size, it becomes
electrically resonant to radio waves of a specific frequency (Figure
1-2). When an antenna is resonant, it will do a much better job of
converting the feeble radio waves to power that can be used by the
receiver. The transmitting antenna is always built to resonate at the
transmitting frequency; so are receiving antennas for communication
purposes, such as CB antennas. The longer the main element of the
antenna, the lower the resonant frequency, as in the case of the piano
Strings,

RESONANT LENGTH

[ . —— . EQUALS ———
! % WAVELENGTH |
!

Figure 1-2. Schematic of half-wave
dipole.
FEEDLINE

_ Acurrent example of a resonant antenna is the Archer FM antenna
in Figure 1-3. It uses two resonant dipoles on one mast,
perpendicular to each other, for omnidirectional characteristics.
Other examples are the CB antennas described in a later chapter.

BROADBAND ANTENNAS

To overcome the need for multiple antennas for TV reception, a
single antenna with multiple elements is used to cover all the chan-
nels. Modern engineering has combined this need for multiple
elements into configurations which increase gain and directivity over
the use of a simple resonant antenna. Figure 1-4 shows a typical TV
antenna.

Figure 1-3. Omnidirectional FM antenna.

Each shorter element helps to direct the signal into the adjacent
longer elements. Each longer element helps to reflect signals toward
the adjacent shorter elements. These actions combine to provide an
increase of signal strength in the direction of the shorter elements and
a decrease of signal in the direction of the longer elements. The result
is a very directional antenna with gain in signal strength. The added
gain helps to receive weak signals, and the directivity helps to reduce
ghosts and images caused by unwanted signals.

DIRECT AND REFLECTED WAVES

The effect of large masses of conductive material on radio waves
can play havoc on TV signals. The best signal occurs when there is a
direct and unobstructed path between the station and your TV set.
This is called "line-of-sight" operation (Figure 1-5.).

MULTIPATH SIGNALS

There may be a direct path between you and the TV station, but if
there is a large mass off to one side (Figure 1-6) you may get two
signals, one direct and one bounced off the large mass. Although
radio waves travel 186,000 miles per second, there is a slight delay in
time between the two signals because of the longer path of the second
one, so one signal is received later than the other. This gives rise to
ghosts in your picture— another image slightly to the right of the
main image. The large mass may be another high building, a

Figure 1-5. Line-of-sight-transmission.

mountain, a water tower, or any other large object that is rape
conductive. This is the reason for the importance of using hig к
directive TV antennas at the receiving end. They reduce, us
sometimes even eliminate, the reflected signal. We will discuss
in more detail in a later chapter. ; d a hill
Sometimes a large building will be in the direct path and а x
produces a secondary path with just as strong а signal, or eyen
stronger. In this case it may even be preferable to point the Д
antenna in the direction of the indirect path and eliminate the poore
direct signal. But only a highly directive TV antenna will do this.

Figure 1-6.

Secondary path can produce ghosts.

СНАРТЕК 2

TV ANTENNAS

TV antennas must be designed to receive a very wide band of
frequencies for the many TV channels, and receive them with highest
possible efficiency. The antenna engineers must be honored for
developing today's design which makes possible such wide-band
coverage, along with high unidirectional characteristics and high
sensitivity. To see the engineering behind an antenna, let us look
briefly at the TV channel frequencies.

Table 2-1 lists the VHF TV channels and the actual frequencies of
the picture signals. Each TV channel also carries a subcarrier for
sound. It is set at just 4.5 MHz higher than the picture carrier
frequency. In addition, a color subcarrier is 3.58 MHz higher than the
picture-carrier frequency. ОНЕ TV channels from 14 to 88 are in the
frequency range from 470 MHz to 890 MHz.

VHF AND UHF ANTENNAS

It becomes obvious that a single antenna of the single element type
cannot possibly cover all the frequencies being transmitted on all the
TV channels. Not only is each TV channel very wide in frequency
needs, but add to that the many channels and the problem is
increased.

Full coverage of the wide frequency spectrum is achieved by the
use of more than one element on a single boom. Each element is ofa
different length, so the combination of all of them results in good
coverage.

The four diagrams in Figure 2-1 carry us through the evolution of a
four-element VHF antenna. Diagram A shows a single element
called the half-wave dipole. In diagram B another element is added,
but of a longer length. This second element resonates at a lower

Table 2-1. УНЕ Channels, Carriers, and Subcarriers*

Frequency Picture Color Sound
Channel Limits Carrier Subcarrier Subcarrier
54-60
60-66
66-72
76-82
82-88
88-108

174-180
180-186
186-192
192-198
198-204
204-210
210-216

* All frequencies in megahertz

frequency and also acts as a reflector for the shorter element. In
diagram C a still longer element is added for a still lower channel (or
lower frequency), and it becomes a reflector for the shorter element
in front of it. In diagram D a fourth and still longer element is added.
It becomes a reflector to the shorter element, as well as resonating
near the low-frequency end of the low-section VHF band, or near
Channel 2. To aid in the directivity of this antenna, the elements are
bent forward.

The illustration in Figure 2-1 shows each element connected to the
lead-in, in a system called cross-phasing. In some antenna designs,
‚я ector and reflector elements are added but not connected to the
ead-in.

The FM band at 88 to 108 MHz is just above TV Channel 6 in
frequency. The broad TV antenna coverage includes the FM band. A

| (A) (B) | |
| : © 2%

Figure 2-1. Evolution of а TV antenna from a simple dipole.

TV antenna will also operate an FM tuner or receiver, and it is
common practice to take a tap off the lead-in to serve both a TV set
and FM tuner or receiver.

The UHF bands are considerably higher in frequency than the
VHF bands. While the frequency range is not broken up into sections
as with the VHF band, they are divided into two parts for two types
of service. Channels 14 to 70 (about 470 MHz to 812 MHz) are for
regular TV broadcasts. Channels 71 to 83 (about 812 MHz to 890
MHz) are for translator service. Translators are located in smaller
communities and act as relays for programs originating in a nearby
metropolitan city. They are automatic in operation; that is, they are
unmanned. Thus, communities too far from regular TV stations have
TV service.

It is obvious the antenna described earlier in this chapter would
operate poorly in the UHF band. The elements are much too long to
be resonant to the much higher frequencies of the UHF band.
Coverage of the UHF band is accomplished by adding a separate
section to the same boom.

Figure 2-2 is an example of an all-coverage antenna, one that
receives VHF, FM, and UHF with high efficiency. Note the
odd-looking front part of the antenna. This part has the short
elements needed to resonate at UHF. The engineering behind it is
generally the same as for the VHF part of the antenna. Usually more
elements are used, because the overall frequency coverage 15
Breater, and more sensitivity is needed to overcome the greater
losses encountered at such high frequencies.

шы ш MUN GUN

Figure 2-2. Ап all-channel TV antenna with separate VHF and UHF elements.

Losses are somewhat greater at UHF than at УНЕ, both in the
transmission and the reception. Hills, trees, terrain, and other
obstructions affect the transmission more at UHF than at VHF.
Television set sensitivity is less at UHF. Losses are greater in the
lead-in. This is why distance specifications on TV antennas are less
for UHF than for VHF.

Where UHF translator TV service only is available, it is
uneconomical and unnecessary to invest in a full-coverage VHF-
UHF antenna. Television antennas and equipment for the reception
of the UHF channels only are available.

The UHF end of the antenna illustrated in Figure 2-2 сап be
purchased separately. This is shown in Figure 2-3.

COLOR TV ANTENNAS

The requirements for feeding a signal from the antenna into a color
set are quite different than for a black and white set. The color
information is carried on a subcarrier of 3.58 MHz on the picture
frequency. Good signal strength is needed to receive this subcarrier
with all its color information. A weak signal would result in a black
and white picture on a color set, along with some “snow.”

If youlive some distance from a TV transmitter you might tolerate
some snow on a black and white set, but you would never be happy
with receiving only a snowy black and white picture on a color TV set.
The extra investment made in a color TV set dictates an extra
investment in a good antenna to assure reception of color TV signals.
Furthermore, don't skimp on a proper installation. Selection and
installation are covered in separate chapters which follow.

MM MÀ M

Figure 2-3. TV antenna for UHF reception only.

CHAPTER 3

SELECTING THE PROPER TV ANTENNA

Probably the most important consideration in selecting an
antenna, but certainly not the only one, is how far your house is from
the TV transmitter. As explained in Chapter 1 the strength of the
signal drops off rapidly with distance from the station. The signal at
20 miles from the station is only one-fourth the strength of that at
only ten miles. This is the effect of the “inverse square law.” With
normal city dwellers, however, distance from station is not that
important. In most cities the transmitting antenna is usually located
on top of a centrally located high building, or on top of a nearby
mountain or hill.

If you are in “line-of-sight” distance from the transmitting tower
from your house even a minimum sized antenna may do the job quite
well. If you are able to see the transmitting antenna, with no
buildings or trees or other major obstructions, you are enjoying the
best possible conditions. But there are other factors which may affect
your decision on what antenna to buy.

In the opposite direction, close in and “line-of-sight” will permit
quite satisfactory results with one of the better indoor antennas, like
that shown in Figure 3-1. See Chapter 8 for more on indoor antennas.

TO ELIMINATE GHOSTS

A ghost is one or more images appearing next to the main image on
the TV set screen. This results when part of the TV signal is delayed
in getting to your set, and the lag in time of arrival means another
image, slightly offset from the first, will be included in the picture
received.

This so-called “multipath” signal will happen when part of the
transmitted signal hits some high point such as a mountain or large

Figure 3-1. A deluxe indoor TV antenna.

building near the transmitter, and reflects some of the signal out to
your receiving position. Figure 3-2 shows an example of this. The
secondary path being longer, the secondary signal takes a little
longer to reach your TV antenna. The extra length of that path
determines how far the "ghost" picture on your screen is displaced
from the main picture. TV antennas with a more highly directional
characteristic will receive the secondary signal path with less
strength and thus reduce, and sometimes eliminate, the effect of
ghosting. Antennas with more elements on them are more
directional. Figure 3-3 is a polar pattern ofa typical highly directional
TV antenna. The outline of the figure represents points of equal
signal strength. In this example a signal only about six or seven
degrees off the main path would have to be half the distance from
your antenna to be of equal strength to the main signal path.
Probably the best way to determine in advance if ghosts may be a

problem at your location is to ask your nearby neighbors about their
experience.

Figure 3-2. Delayed signal from secondary path can produce ghosts.

Another factor affecting an antenna purchase is the number of TV

and/or FM sets that are to be operated from the one antenna. In
today’s multiset homes it is not necessary to purchase separate
antennas for each set. There are distribution transformers or
couplers that make it possible to connect any number of sets to one
antenna, with only one important effect—the available signal power
received is divided among the number of sets connected. This means

Figure 3-3. Polar pattern of a
highly directional
antenna.

SS;

a larger antenna should be used, to assure there will be enough signal
strength for each set. The ЕМ band falls between the low and higher
VHF TV bands. A TV antenna can also serve an FM receiver or
tuner by using one ofthe outputs ofa coupler, the same as another TV
set.

The height of the antenna above ground adds a great deal to its
ability to receive signals from a distance. In city and suburban areas
itis usually sufficient to just mount the antenna on top of the house, or
even in the attic. Homes in the country, on the farm, or ranch distant
from the transmitting antenna pose a different problem. There,
height becomes very important and often requires the investment in
a 50-foot or higher tower. It may even require the addition of
amplifiers to boost the signal. More about these later.

Table 3-1. Specifications on Archer TV Antennas

Archer Range in. Miles Boom No. of
Model Length Elem.
48
E 40

160" 15-1646
140 15-1645
120" 35 15-1644
100" 30 15-1643
80" 25 15-1642
50" 15-1641
40" 15-1640
160" 15-1654
80" 15-1652
50" 15-1651
30" 15-1650

Another factor in antenna choice is the TV bands in use in your
area. If TV service is only in the band which covers channels 2
through 18 a VHF antenna like that shown in Figure 3-4 will do. In
some cities the UHF station or stations are not at the same location as
the VHF stations, but in a different direction altogether. That means
you may need to install a second antenna, one which serves the UHF
channels separately (Figure 2-3).

Rotators are often used on TV antennas to turn them to a different
direction. Homes in the country may need a rotator when TV
reception is from cities in different directions. Antennas with greater
signal gathering ability are also more directional in characteristic, so
they must be turned in the direction of the transmitter to pick up the
signals.

Radio Shack makes it easy to select a TV antenna by their model
number designations and by charts published in the catalog.
Reproduced in Table 3-1 are the figures from their charts. The

Figure 3-4. А VHF-only TV antenna.

Archer brand model numbers are preceded by a VU for antennas for
both VHF and UHF signals, a V for antennas designed only for
Channels 2 through 13, and a U for antennas for UHF use only. The
numbers following the letters are the approximate miles the antenna
Will reach for good signal reception. The figures apply to the use of
one antenna for one TV set. When the signal must be divided among
more sets, or to include an FM tuner or receiver, an antenna with a
higher figure should be used.

Note from the charts, maximum range in miles is related to
both boom length and number of elements. In the case of the VU
models the number of elements include those in the UHF part of the
antenna structure. Note, also, the distances covered are less for
UHF and FM services. Frequencies in the UHF range are so high
that losses in signal transmission, in lead-in cable and other fac-
tors, call for longer booms and more elements for the same
distance of coverage. For FM reception a strong signal is needed
to supply good stereo separation.

CHOOSING THE ANTENNA

The mileage coverage shown in Table 3-1 for Archer antennas
presupposes nearly line-of-sight locations between the transmitting
and receiving antennas. Obviously you would not be expected to
actually See a transmitting antenna 160 miles away, but one can
assume it is in line-of-sight if on top of a high mountain at that
distance. If the transmitting antenna is not on a high mountain, but
on a building that is, say, only about 10 stories high, the horizon

between you and the transmitter reduces line-of-sight effectiveness.
Considering the investment on one or more color TV sets to work
from the antenna, it is better to err in favor of a larger antenna since
the increased cost of the antenna is only a small part of the total
investment in good TV reception. As an example, if you are 50 miles
from the transmitter and there is not true line-of-sight conditions or
you are in doubt, select an antenna with a 100 mile figure or greater.

When obstructions are in the way there is great loss of signal.
Should there be tall buildings in the signal path, or heavy trees, the
loss would be greater in summer when the trees are in full leaf. In
such cases the antenna to select should be two steps above the
idealized one on the basis of mileage.

Attics sometimes have the space to hold an antenna, and some
people prefer to use it. Because of the lower height, and the usual
obstructions associated with the use of an attic, select an antenna
one or two steps above the minimum.

For UHF and FM reception, the mileage figures are shown
separately in the charts. However since the FM set represents
another hookup to the antenna, an antenna of double the mileage
figure shown should be selected.

Where multiple sets or TV sets plus FM tuner are to be operated
from the same antenna, couplers should be used to divide the signal
among them. While couplers are the most efficient way of dividing
the signal there is some signal loss in couplers. Divide the distance
figure by the number of sets to be connected to the antenna to select
the mileage figure that applies.

Ghost images are probably the biggest bugaboo in the reception of
good quality pictures. Even transmitting antennas on top of high
mountains are not always the answer. The signal can bounce off
another nearby mountain and result in a multipath signal. Only the
experience of others in the neighborhood can be of assistance in
selecting the proper antenna. The greater the number of elements in
an antenna the greater its directivity, and directivity is the most
important quality needed to reduce ghost images. It is sometimes
necessary to make some adjustments on the direction to which the
antenna points at the time of installation. There are occasions where
better overall results are obtained when the antenna is pointed
slightly to one side of the direct path because it may reduce the

reflected path to a greater degree and overall results are much
better.

TV FOR RECREATIONAL VEHICLES

For the family on the go there is an antenna in the Archer line
especially suited for them. Figure 3-5 shows a standard design TV

Figure 3-5. Mobile TV antenna. Elements fold down for traveling.

antenna with elements for VHF, FM, and UHF. It is supplied as a
complete kit with all necessary hardware for mounting the antenna to
the side of the RV. The antenna folds down while traveling to reduce
wind resistance, and snaps up for operation. Turning for direction
orientation is done by hand.

Figure 3-6. Mobile VHF-TV antenna.

An Archer line VHF-TV antenna for vehicles on the move is
shown in Figure 3-6. This allows passengers to enjoy reception in
limos, cars, vans, and trucks while traveling. In areas of weak FM
reception, this could also be used to improve the FM signal.

CHAPTER 4

SPECIAL ANTENNAS FOR FM

The FM frequency band range is 88 to 108 MHz. It starts just off the
high frequency end of TV Channel 6. That is why a TV antenna also
receives FM signals quite well, and the same antenna can be shared
between a TV set and an FM tuner or receiver.

THE RESONANT ANTENNA

Since the FM band is only 20 MHz wide, an FM antenna of simple
design can be considered pretty nearly resonant in the FM band. This
is why a single element antenna, or single dipole as it is called, does a
good job of F'M reception. A dipole about 60 inches long is considered
resonant in the FM band. At this length it becomes a half-wave
dipole, the usual term used in engineering parlance for the simple
resonant antenna. Figure 4-1 is a drawing of such an antenna.

UNIDIRECTIONAL AND OMNIDIRECTIONAL
ANTENNAS

Too often FM transmitting towers are not all located in a single
area, as mentioned before. Where this is true, good reception from all
stations requires an antenna that has good pickup from all directions.
This type of antenna is called an omnidirectional or polydirectional
antenna.

The antenna illustrated in Figure 4-1 would have a polar pattern
that would look like a figure 8 (Figure 4-2). It would be good for
pickup in the two opposite directions. The antenna of Figure 4-3 is
two folded dipoles at right angles to each other. The polar pattern
becomes two figure 8's at right angles (Figure 4-4). Now we have
essentially an omnidirectional antenna. In practice the patterns

e " І
H 60 ES
| 1
|
0
Figure 4-1. Folded dipole antenna for FM band.
———--. =.
“7 EN — 4
/ Б Pd Ў Figure 4-2. Pickup pattern of
! NP x gure 4-2. ckup pattern
\ AN | single dipole antenna.
\ ^ EN /

illustrated are never exact, as they are affected by surrounding
terrain and other conductive objects and nearby wire systems.

Figur e4-5 is another omnidirectional antenna. As can be seen, the
antenna is a single dipole but bent into an “S” curve. This will distort
the normal figure 8 pattern and result in good omnidirectional
pickup. The antenna of Figure 4-3 is to be preferred for best
all-around pickup.

Figure 4-3. FM antonna with two folded dipoles sot at right angles.

Figure 4-4. Polar pattorn of antenna
shown in Figuro 4-3.

Figure 4-5. S-curve omnidirectional FM antenna.

STEREO RECEPTION AND ANTENNAS

Ifyou have a good FM tuner or-receiver you probably know it has a
published sensitivity somewhere between 0.5 uV and 5 LV. Thisisa
considerably higher sensitivity figure than for TV sets. This means
that just about any old piece of wire connected to the antenna
terminal will give you good enough reception, and often does. But
"good enough" is not good enough when it comes to hi-fi stereo
reception.

As in the case of color TV transmission with its 3.58 MHz
subcarrier, the FM signal includes a subcarrier of 19 kHz. This
subcarrier carries the multiplexing information needed in the
receiver or tuner to separate the two channels of audio with a
minimun of overlap. This 19 kHz signal is transmitted at one-tenth
of the FM modulation. If the subcarrier is lost in reception the
stereo will be lost or so degraded that good separation of the two
audio channels is not “hi-fi.” In other words the two channels of
audio will not be separated, but heard as a monophonic or single
channel audio. Sometimes the signal is borderline and the stereo ef-
fect falls in and out as you listen, and this can be most distressing.

Furthermore, good noise reduction from both external and
internal noises (circuit noises) requires a good strong signal at the
input to be really effective. So, what it comes down to is that in spite
ofthe high sensitivity of good tuners or receivers, it is still necessary
to receive a strong signal for high-fidelity results. Figure 4-6 is an
example of a multielement antenna design that will provide the
signal strength needed for good stereo FM reception. It is designed,
of course, to provide FM reception at a great distance as well, having
a range of 175 miles. A similar antenna but with less elements has a
range of 110 miles.

The multielement antennas described above have another, and
very important, advantage. These antennas are also highly
directional and this is an important characteristic for FM. In the case
of TV a multipath signal will result in a ghost image on the picture
tube. In the case of FM it results in distortion. The radio waves
radiate out in all directions from the transmitting antenna. If there is
a high hill or a building nearby some of the signal will bounce off the
hill or building and create a secondary wave. The secondary wave
path from the transmitter to your location is longer and takes a bit
longer to reach your antenna. Because of this there is a phase lag
between the direct and indirect signals and this can result in what
engineers call phase distortion. As in the case of TV a highly
ын antenna at the receiving end will reduce or eliminate this

ect.

_ The very best FM reception is provided by the use of both a highly
directional antenna and a rotator. The rotator not only allows you to

Figure 4-6. A highly directional FM antenna.

swing the antenna in the direction of the FM transmitter, but also
permits slight adjustment of the antenna direction for maximum
reduction of secondary path signals. Very often aiming the antenna
just a couple of degrees off the actual direction from the wanted path
will have a great effect in reducing the signal from the secondary
path, and reducing distortion.

Chapter 5

FRINGE AREA TV/FM ANTENNAS

The word fringe means the outer area of good TV reception,
beyond which enjoyable reception should not be expected. It may be
defined as somewhere between 100 and 150 miles, the extremes of
which might be named near fringe and deep fringe. The words are
rather nebulous and even the distances are not clear, as so much
depends on other factors and not just distance. Conditions of ter-
rain eount as much as distance.

DISTANCE AND SIGNAL STRENGTH

In Chapter 1 we discussed the similarity between light and radio
waves, and the loss of signal based on the inverse-square law. Signal
lossis related to the square of the distance. At 50 miles a signal is only
one-fourth as strong as at 25 miles. At 100 miles it is only
one-sizteenth as strong as at 25 miles. The sketch of Figure 5-1 is

=} pAT GIVEN d=1,

pAT2d=1 5 Figure 5-1. The inverse-square
>= (2d) law.

pAT3dz1

1 D
id= DISTANCE
jP=ROWER

another method of showing this. To make an even more extreme
comparison, city folks living at about 10 miles from a TV transmitter
have no problem with TV reception on the basis of distance only.
Their “country cousins” living 100 miles from the same transmitter
are faced with receiving a signal only one-hundredth as strong, so
they must take special steps to make the best of that weak signal.

The inverse-square law is based on free-space conditions; that is,
with nothing else interfering. But at the surface of the earth other
things do interfere—the horizon and hills or rolling terrain.

Light bends very slightly around the curvature of the earth. The
prism effect of the denser atmosphere near the surface and lighter
atmosphere higher up is what puts a small bend in light. Radio waves
will follow the curvature ofthe earth much more than light waves, for
reasons other than the prism effect of the atmosphere. At low radio
frequencies the bend is considerable. This is why you can pick up
broadeast stations at night a thousand or more miles away from your
carradio as you travel across country. (Long distance transmission is
better at night due to rearrangement of the ionized layers.) At higher
radio frequencies, radio waves begin to act more and more like light,
and the ability to follow the curvature of the earth is less. At TV
frequencies the bend is quite small. Hills and other rises in the earth's
terrain are even more difficult to overcome. This is why great height
is needed, both on the part of the TV transmitter and on the part of
the receiving antenna.

А homeowner at a distance from a TV transmitter and in a valley
has an almost insurmountable problem in bringing TV entertainment
into his home. An individual can install an antenna at the top of a
nearby hill, connect an amplifier, and run coaxial cable down to his
home. This becomes a rather expensive installation. Communities in
a valley will usually contract for a community television installation
and service. This is called CATV. A company will install a very
high-gain antenna on a hill, amplify the signal from it, and feed the
signal to the homes in the community by coaxial cable. A fee is
charged to bring the cable into the home, and a monthly service
charge helps maintain the equipment.

These days greater use is made of satellite TV transmitters, called
translators. They are usually installed in smaller communities by the
operators of principal TV stations in a larger city. The main TV
station uses microwave transmitters to send their programs to the
translator, which then retransmits the programs to a local area.
Translators are usually low in power, but cover the local community.
They are maintained by subscription from local residents. Not all
communities in a state-wide area are covered by translators.

Translators are usually operating on Channels 14 to 70, in the UHF
range.

LONG-RANGE ANTENNAS

To assure good fringe area reception of TV, a high-gain antenna
mounted as high as possible is required.

The antenna in Figure 5-2 is an example of an all-coverage antenna
for fringe use. It covers the VHF and UHF TV bands as well as FM.
With a total of 40 elements it will receive TV signals on the VHF band
up to 160 miles, and on the UHF and ЕМ bands up to 100 miles.

Ifthe TV stations around you broadcast service in Channels 2 to 13
only (the VHF TV band), the antenna in Figure 5-3 has more gain
than the one in Figure 5-2 and at less cost. With its 34 elements it will
bring in TV signals from up to 185 miles, and FM up to 110 miles.

In many areas, stations serving the fringe areas transmit only on
the ОНЕ channels, 14 to 70. Also, sometimes the ОНЕ translators on
Channels 71 to 83 will be quite a distance from your home. In any
case, the UHF antenna in Figure 5-4 is a UHF-only TV antenna
capable of picking up signals in the UHF channels up to 100 miles
away. It is highly directional.

NEED FOR HEIGHT

" The one factor for successful reception of TV in fringe areas, that of
igh-gain antennas, was described above. The other factor is the
need for great height to overcome the effect of the horizon or other
у obstructions. Height is important for both the transmitting and
receiving antennas, The TV stations use the highest economical

Figure 5-2. А 40-element all-channel TV antenna.

Figure 5-3. A 34-element VHF-only TV antenna.

Figure 5-4. A long range UHF TV antenna.

locations they can in order to serve as many viewers as possible. The
height of the receiving antenna is up to the owner of the TV set.

One ofthe best ways of deciding just how much height is needed for
your location is to check with neighbors in your area. However, keep
afew points in mind when checking with your neighbor. Is he using a
black and white set? How much snow, if any, is there in the picture?
How doesthe antenna compare with the one you plan on installing? Is
he located on higher ground than your location? If you want a good
color reception, you will need a better installation than one for black
and white.

MASTS AND TOWERS

The usual method for installing a TV antenna at great height is
atopa mast ortower. Masts, like the one shown in Figure 5-5, come in
19-, 27.5-, and 36-foot lengths. They are made in sections with
graduated diameters that telescope into each other. The steel masts
are hot-dipped galvanized and zine coated for weather protection.

A steel stake and plate is used to keep the mast from sinking into
the ground or moving horizontally, see Figure 5-6. .

Towers are triangular or squareshaped structures with cross

Figure 5-5. Telescoping steel
mast.

girders. They are usually made of steel. They are considerably more
expensive than masts.

Itis extremely important in the installation of a mast or tower to be
sure it will withstand the highest possible wind that may be
encountered in your area. Highest winds normally encountered are
about 80 miles per hour, with some exceptions. The exceptions are
along the Atlantic seaboard and the coastal borders of the states
along the Gulf of Mexico. In Wisconsin, along the shore of Lake
Michigan, winds are known to exceed the 80 miles per hour
mentioned.

It is always best to include a safety factor. A 30% safety factor is
recommended by the Electronic Industries Association, which
means for highest normal 80 mile-an-hour winds, figure on about 110
miles per hours.

Towers up to fifty feet can usually be installed without guy wires.
A three-foot square hole is dug. The mounting feet usually supplied
with the mast are put in place, properly spaced to fit the bottom ofthe
tower, and about a yard of concrete is poured into the hole. When the
concrete is set, two ofthe bottom feet ofthe tower are fastened to the
mounting feet, and the tower pulled up into place. Steel towers are
quite heavy, and will probably require the use of a gin pole, a tackle
line, and two or three husky men to put them up (Figure 5-7).

Masts are not only less expensive, but considerably lighter in
weight. A 36-foot mast only weighs about 30 pounds. All masts must
be guyed, which means there must be enough room around the mast
location for the guying stakes. Guying stakes should be placed about
10 feet from the base for each 20 feet of mast height. Radio-type, 6/18
guy wire is sufficiently strong to hold a 36-foot mast in any wind. Size
6/18 means six strands of size 18 galvanized iron wire twisted
together. Stakes may be commercial type such as used for anchoring
fences or guying telephone poles, see Figure 5-8, or steel fence posts
driven into the ground to within a few inches of the top.

Figure 5-6. Mast base mount.

Figure 5-7. Using a gin pole to raise a TV tower.

S)
g
QS
Qa)
QB)
QR)
QL)
J P

(B) Auger type.

(A) Screw type.
Figure 5-8. Screw-in guy-wire anchors.

Masts are light enough to be mounted on the roof of a house or other
Structure. It requires careful calculation of the length of the guy
wires, which are fastened in place before the mast is raised onto the
roof. Figure 5-9 shows how this is done. The mast can be walked up
after the guys are in place. Be sure the guy eye-screws are fastened
into roof rafters, or they will surely pull out with a high wind.

The TV antenna, and rotatorifused, must be installed on the tower
or mast before they are raised. All lead-in and rotator cables must be
connected and run down with standoff insulators beforehand. The
antenna must be correctly oriented if a tower is used, as a tower
cannot be rotated after it is up. A mast, however, can be rotated after
it is in the vertical position.

If TV transmitters are located in different directions, or if an
offside hill develops a secondary signal path, a rotator is highly
recommended. Rotators are geared-down, electric motors that turn
the antenna to the direction desired.

Figure 5-9. Setup of TV mast preparatory to walking it up to the peak of the
house roof.

Ап important precaution: Be sure to install your antenna far
enough from any electric lines so that it will not fall onto the lines in
case it is blown down. Also consider any possible damage to buildings
or other structures nearby, either those of your own, or those of your
neighbor's. Leave plenty of room around your antenna system.

To make a secure guy-wire connection be sure to use two or more
wraps around the eyelet and then at least 10 or more tight turns
around the guy as shown in Figure 5-10.

GUY WIRE

TWO OR MORE
TURNS
ANCHOR

EYELET 7—10 OR MORE

TURNS

Figure 5-10. Guy-wire connection.

Another method of guy wire connection makes use of guy-wire
clamps as shown in Figure 5-11. When using these clamps, be sure the
"U" bolt compresses and deforms only the short free end of the guy-
wire. This keeps the strength of the guy wire at its maximum. Large
size guy-wire which is difficult to twist tightly around itself should
use guy-wire clamps as shown in Figure 5-10.

ЕВЕЕ
END

“TWO OR MORE
TURNS

Figure 5-11. Guy-wire connection using clamps.

When using a high antenna installation, you will need longer 75- or
300-ohm lead-in. Don't make the common mistake of using normally
bad cable. Use the best grade of low-loss cable you can afford or all
your increased signal pickup will be lost in the cable, and the entire
effort will be to no avail. Some older installations suffer from no more
than lossy lead-in.

An important precaution: Be sure to install your antenna far
enough from any electric lines so that it will not fall onto the lines in
case it is blown down. Also consider any possible damage to buildings
or other structures nearby, either those of your own, or those of your
neighbor's. Leave plenty of room around your antenna system.

CHAPTER 6

MULTIPLE-SET DISTRIBUTION

More and more homes now have two or more sets. Two-set homes
may nearly equal, ifthey do not already exceed, the number of homes
with one TV set. Also operating an FM tuner or receiver off the same
antenna with a TV set is quite popular.

Assuming a reasonably good antenna and a reasonable distance
from the TV station, along with the high sensitivity ofthe modern TV
set, there is no reason why more than one set cannot be operated

from a single antenna. In doing so, however, it is advisable to observe
certain rules for best results.

IMPEDANCE MATCHING

When the impedance rating of the antenna is equal to the lead-in
impedance, there is a maximum transfer of power. This is also true for
the end of the lead-in where maximum power transfer is also depen-
dent on equal line and termination impedances. Any condition which
upsets this required impedance match will cause less power transfer
at both the source and termination of the line, and an increase in loss
of energy all along the line. For these reasons, the impedances must
always match or the installation may waste so much energy that pro-
per reception would be impossible on one or more stations. Figure 6-1
shows an improper connection of two TV sets on a 300-ohm lead-in.
Each set presents a load of 300 ohms, so the net load effect on the line
at the table model TV is 150 ohms, as shown in Figure 6-2. This
analogy of two parallel resistors illustrates the mismatched im-
pedance on the load end of the lead-in, but this improper connection
also causes a mismatch at the antenna. This antenna-to-line
mismatch depends on the length of line and the frequency of the

signal. The full effect of a mismatch like this cannot be illustrated
simply.

Figure 6-1. Improper connection to two TV sets.

NET LOAD

ta-
Figure 6-2. Schematic represen
EFFECT 1509 300 2

tion of Figure 6-1.

Impedance matching is obtained by the use of RF transformers in
the e way PA eee are matched with o ee
These RF transformers are generally about 90% efficient so a n
them is much less than would occur if they were not used.
transformers are commonly called splitters or couplers, depending on
their application. .

TUO Tes of impedance-matching couplers are generally оо
able. Figure 6-3 shows а two-set coupler. It has three sets of s М
terminals. One set is for connecting the lead-in. The other two a
the two sets. The same kind of 300-ohm lead-in wire may be phe р xpi
the coupler to the TV sets. This is the way it is usually done, wi =
coupler located somewhere convenient to both sets. Figure ve 5 е. т
а four-set coupler. The five sets of terminals are for the lead-in, а

INDOOR TY TV FM 3 SET COUPLER "m
© © 9.9
ө ө 0
Figure 6-3. Two-set coupler divides Figure 6-4. A four-set coupler.

the single input signal to
two output signals.

INDOOR TY TV/FM 2 SET COUPLER Ф
ы

TO ANT

for the wires to the four sets. It should be located where a
distribution cable to each set can be kept to a minimum length.
Figure 6-5 shows how to connect a two-set coupler. The coupler
itself should be located at a point where it results in a minimum
overall amount of cable run. If in-the-wall lead-in installation is used,
a good place for the coupleris in the attic. The same hookup is used for
a TV set and an FM tuner, substituting the tuner for one TV set.

X Бе
300-0 TO SET

Figure 6-5. How to connect a two-set coupler.

What do you do when you want to connect to only three TV sets, or
two TV sets and an FM tuner? Use a four-set coupler. However, it is
best to connect a “dummy load" to the fourth terminal set. All this
means is to connect a 300-ohm 5%, or 270-ohm 10% value resistor to
the terminals. While this results in a waste of some of the power, it
does maintain the impedance match. These resistors may be pur-
chased at Radio Shack.

Figure 6-6 shows the hookup for a four-set coupler. In this diagram
three TV sets and an FM tuner are connected to the coupler, and all
are operated from a single antenna. Figure 6-7 shows what a resistor
looks like. To substitute the resistor for a TV set, merely bend the
two leads of the resistor, twist one lead around each of the screw
terminals of the unused set (Figure 6-8), and tighten the screws.

LEAD-IN

Figure 6-6. Connecting three TV sets ТО TV SET #3
and an FM tuner to one
antenna.

TO FM TUNER

Figure 6-7. An oversize view of а Figure 6-8. How a resistor is con-
typical carbon-composi- nected across an unused
tion resistor. coupler output.

Multiple-set distribution to 75-ohm color TV sets using coaxial
cable follows the same rules as for 300-ohm cable described above,
except the figures are in terms of 75-ohm impedances to be matched.
Figure 6-9 illustrates a four-set coupler for 75-ohm coaxial cable.
Instead of screw terminals cable connectors are used. The cable ends
must include mating plugs on them at each end of each cable. Cables

ly prepared with connectors on them are available in 2-, 4-, 8-,
50-, and 100-foot lengths, You can make your own by purchasing bulk
75-ohm coaxial cable and the plug connectors. А

Multi-set couplers must not have empty output connectors. As іп
the case of the 300-ohm type couplers, where a 300-ohm resistor is
connected to the unused screw terminals, the coaxial-type couplers

INPUT, а
WARCHER> 2
4 Set UHF/VHF/FM
Coupler/Combiner

CAT. NO. 15-1142
SET 1 sET2

ЗЕТ З

Figure 6-9. Four-set coupler for 75-ohm coaxial cable.

must use 75 ohm 5%, or an 82 ohm 10% value, connected to empty
connectors. Use a coaxial plug and install a 75-ohm resistor. One lead
of the resistor will be the inner conductor by passing it through the
center hole; the other lead is wrapped around the outer shell and
soldered to it. Leave only about 4” of center lead sticking through the
center, cutting off the rest.

300-ohm and 75-ohm cables and how to connect a plug to 75-ohm
cable are illustrated and described at the end of the next chapter.

Sometimes conditions are such that it is more convenient to place
the coupler outdoors and run separate lead-in wires into the house to
the individual sets. Figure 6-10 shows a two-set splitter/coupler, but
in a weatherproof housing, and with clamps for fastening it to the
mast holding the antenna. A mast-mounted, four-set coupler is also
available.

Figure 6-10. Atwo-set couplor
made to mount
on the antenna
mast.

In small apartment buildings, up to eight sets may be fed with the
same antenna. One two-set and two four-set couplers can be
connected into a distribution system as shown in Figure 6-11. Since
you will be dividing the available power by eight, a good antenna
must be put up and installed as high above the roof as practical.

AMPLIFIED SYSTEMS

It is important to keep in mind the more sets that are connected to
a lead-in the less signal is available for each set. The loss is actually
more than merely dividing the available signal by the number of sets.
Couplers are the most efficient way to make multiple-set connections

to one antenna, but these devices do have some loss inherent in
themselves.

Figure 6-11. A two-set coupler feeding into two four-set couplers.

If youare at a distance from the TV transmitter, or your antenna is
not line-of-site in its location, using more than four sets (including
FM) may require amplifying the signal to give good results. In large
apartment buildings, hotels and motels, a good amplifier is a must for
feeding distribution couplers to so many sets. While the amplifiers
are powered by the AC lines, they are designed to draw very little
current from the line, and may run 24 hours a day at low cost. They
are transistorized and may run for years without need for service.

type of amplifier builds up the signal from the TV antenna to
се any noise pickup from the lead-in and following distribution
es.

Figure 6-12 shows one such amplifier. The amplifier itself is
mounted to the mast right where the connection is made to the TV
antenna. The power supply which operates the amplifier is mounted
indoors. The lead-in used for the TV signal also carries the power up
to the amplifier. A separate cable for this purpose is not needed.

When additional amplification is needed, or for a large number of
TV sets, additional amplifiers should be added indoors (Figure 6-13).
The output from the mast mounted amplifier feeds one of the indoor
amplifiers, which in turn feeds other couplers, four in all in the case of
the one illustrated, or other amplifiers like it.

Additional amplifiers are placed at distribution points, then cables
are run from them to the TV sets. These amplifiers also have built-in
couplers. General practice is to use 75-ohm coaxial cable throughout
the system.

Amplified systems are a little beyond the capabilities of the
average home mechanic. Their installation is best left to the

Figure 6-12. Signal amplifier. Weatherproof, mast-mounted amplifier at loft;
power supply at right.

professional organizations, who are better equipped with the
necessary tools and knowledge.

It must also be remembered that an amlifier needs a good signal at
its input to obtain a good signal at its output. Therefore don't expect
an amplifier to make up for a poor antenna or antenna location.

INTERCONNECTING CABLE

Coaxial eable is round and small in diameter. Running the cable
from antenna to coupler to sets poses no problems. However, it is
expensive, and there is a need to install plugs onto the ends of the
cables.

Three hundred-ohm twin lead distribution is less expensive than
coaxial cable, and connecting it to couplers and TV sets is a simpler
job. It is only necessary to strip a little insulation off the ends and
wrap the wires around the screw terminals and tighten down on the
screws. Some couplers even have clawlike washers under the screw
heads which bite down through the insulation and eliminate the job of
stripping. This is not true at the TV set terminals, however.

The only precaution that must be observed in running twin-lead
cable around is to avoid coming near large amounts of metal. The
cable should not be run near or parallel to electric wires, or water or

pet

e
|
' COLOR SUPREME
| AMPLIFIER/COUPLER
=
e ә

| =

ü B

i à
=. . B

CAUTION Э
TO PREVENT ELECTRIC SHOCK DO Al
NOT OPEN. NO USER SERVICEABLE
COMPONENTS INSIDE. REFER SER- 4
VICING TO QUALIFIED SERVICE H
PERSONNEL

e
e

фі

Figure 6-13. Ап indoor TV signal amplifier designed for use with 75-ohm
coaxial cable.

gas pipes. There should be a distance of at least four inches from such
metal. Shielded cable eliminates this precaution.

Running twin lead around the wall molding is fairly easy except
when going from one room to another. Running it around door
openings poses a problem and requires a little ingenuity. Special
tacks are available to hold the cable in place against the floor molding.
Since some 300-ohm cable is clear, there usually is no problem of wall
color matching.

The best way to feed cable to the sets is through the wall, and is
fairly easy in a one-story home with an attic. The lead-in may be
brought into the attic from the antenna either directly through the

roof, or around over the edge of the roof overhang (or via the
basement or crawl space). The coupler is fastened to the top of a
ceiling joist, or to a roof rafter. Or it may be just laid on top ofa ceiling
joist without fastening. Nothing will disturb it. The cables to the
individual sets are dropped through holes in the wall plate to points in
the wall near each set.

The inner walls of nearly all homes have 2 x 4 studs between the
plaster boards. No insulation is used in the inner walls and, usually,
there is no obstruction to dropping the cable to a point about a foot
above the floor line. In some cities the fire codes require firebreaks
(fire stops) in walls. These are horizontal pieces of 2 x 4 studs about
halfway up the wall. Going through these poses a problem. If your
home has a basement or crawl space, coming in from below avoids the
firebreak pieces.

The best way to do an in-the-wall installation is at the time the
homeis being built. Just before the plaster walls go up is an ideal time
to get in and run the cable.

Fishthe cable through a hole cut into the plaster nearthe TV set. A
better way is to install a TV antenna outlet (Figure 6-14).

Figure 6-14. А wall socket and matching plug for 300-ohm twin-lead.

More expensive but by far the best way to feed TV sets with
connecting cable is to use coaxial cable. It is small and round, and
easy to handle. Furthermore, its 75-ohm impedance matches the
input of color TV sets. Stripping coaxial cable and installing plug
connectors is a bit tedious but not really hard. No soldering is
required. The cable consists of an inner conductor and outer shield of
braided wires, then an insulating cover over all. Color TV sets in
most cases have the coaxial type connectors on them. The plug end of

as cable is plugged into the connector on the TV set, and screwed in
place.

The same cable is used from the antenna to the coupler or
amplifier, and to individual sets. Ifthe cable is run inside the wall, use
wall outlets made with coaxial connectors on them. Make up short
cables with plugs to run from the wall outlets to the TV sets. These
ready-made leads can be purchased from Radio Shack in 2-, 4-, or
8-foot lengths.

The following chapter gives more about the installation of coaxial
connectors.

СНАРТЕК 7

HOW TO INSTALL A TV
ANTENNA

Television antennas are really quite easy to install. They are made
so by most manufacturers of TV antennas, and it is especially true of
the Archer line, sold exclusively by Radio Shack.

When you buy an antenna, the package you get is much smaller
than the antenna. This is because the long elements on the antenna
are folded flat against the boom, like the wings of a bird folded against
its body. No tools are needed to ready the antenna for installation.
The elements are unfolded by hand. Specially designed swivel joints
snap the elements into place when they are opened. In fact, it is
impossible to refold the elements without damaging them, that's how
securely they are held in place. When completely unfolded the
antenna appears as shown in Figure 2-2. The elements of the UHF
front section are so short they do not need folding, so are fixed in
place.

Very complete instructions are supplied for unfolding and
installing your antenna. Although the instructions are complete, the
language used is compact and terse. Also included with Archer
VHF/FM/UHF antennas is а VHF/UHF splitter, the use of which
will be covered later.

The larger Archer antennas, models VU-190, VU-160, VU-120, and
У-185, аге of twin-beam construction. The lower and shorter boom is in-
stalled on the mast first, oriented for direction, then the main
antenna is snapped onto the smaller boom. The smaller boom
becomes a cradle mount assembly. It permits the installer to open out
all elements of the antenna, then just snap it into place. It eliminates

the cumbersome job of mounting a large and unwieldy antenna
directly onto a mast.

ROOF MOUNTING

The most popular place to mount a TV antenna is on the roof of your
home. If you are located close to a TV station, and your house is
orientated correctly, the antenna may be mounted in the attic. In
deep fringe areas even the roof level of the house may not be high
enough, and a high tower or mast is needed. But for average
metropolitan and suburban distances, the roof of a home usually
provides a good height for the antenna.

_Inaddition to the antenna and a mount, you will need a metal mast,
either five feet or ten feet long. These are standard TV items in all
Stores selling TV antennas. They are available at Radio Shack in gold
ae” steel. The ends are swagged to permit stacking to greater

eights.

There is a large variety of hardware items available for mounting an
antenna on the roof. One of the sturdiest is the tripod type of mount
shown in Figure 7-1. It is fastened to the peak of the roof or onto a flat
roof. Normally a five-foot mast is fastened to the antenna, and the
assembly is inserted through the apex of the tripod and through the
center brace, for a two-point hold onto the mast. When purchased,
the tripod is in a long, but narrow box, as the center brace folds for
easier packaging. The bottom feet are adjustable for slanting to
match to roof lines, For greater height, a 10-foot mast may be used in
this mount. Я

The roof mount of Figure 7-2 has hinged base plates for adjusting
tothe roof slant. It is built of heavy-gauge material and will support a

antenna опа 5-ft mast without additional guying. If a 10-ft mast is
used, guy wires should be run from about the middle of the mast to

BUy screw eyes or hooks in the roof.

1
1
1

>
Q

Figure 7-1. Tripod roof mount. Figure 7-2. Roof peak mount.

Both ofthe roof mounts just discussed are fastened to the roof with
long wood or lag screws. The screws must be long enough to go
through the shingles, or tar paper, whichever is used, and into the
wood below. If possible, find the location ofthe roof rafters under the
wood sheathing beneath the shingles; long serews make a more
secure hold when they also grip the roof rafters. Be sure to daub the
areas around the screws with an asbestos-filled roof tar. It is
available as a patching tar, in quart cans, from most hardware stores
and hardware departments of department stores.

Vent pipes are very secure methods of holding a TV antenna mast.
Vent pipes are usually four inches in diameter, and extend through
the roof from bathrooms, the laundry area, or kitchen. A two-piece
clamp for holding the mast is best. Figure 7-3 shows the bottom of the
mast fastened to a vent pipe, using this type of vent clamp.

Figure 7-3. A two-piece vent-pipe
clamp and mounting.

CHIMNEY MOUNTING

One of the more common methods of mounting a TV antenna is to
attach it to the chimney. A number of mounting hardware types are
available for this. All use the principle of banding the chimney with
stainless steel straps and securing, by means of the bands, the
mounting hardware that holds the TV mast.

A popular chimney mount is shown in Figure 7-4. A single strap
holds a V-shaped vertical piece to the chimney. A V-shaped part

Figure 7-4. A husky, single strap Figure7-5. AZ-typechimney mount.
chimney mount.

against the chimney corner is .05 inch steel. This is fastened to an
embossed horizontal section of 12-gauge steel. U-bolts in the
horizontal sections hold thé TV mast. Figure 7-5 shows the popular
Z-mount, the separate parts of which are in the photo of Figure 7-6. A
Set of two-Z-mounts is required to hold a TV mast.

Both of the mounts above use eye-bolts with one side flat to hold
the stainless-steel straps. Nuts on the threaded parts of the bolts
draw the straps up tight around the chimney.

The ratchet chimney mount of Figure 7-7 also uses straps around
the chimney, but it employs a different method of tightening the
straps. A ratchet system, detailed in Figure 7-8, pulls up tight on the
strap when turned by a wrench. The idea is a clever one, and some
may think this is an easier method of tightening the straps. The nut
method of tightening is a little slower but is just as secure when done.

If the chimney is brick, and it appears that some of the mortar has
loosened from aging, it would be best to have it tuck-pointed before
installing a chimney mount. A poor mortar condition can be made
worse from the wind whip on a TV antenna when mounted to the
chimney.

WALL MOUNTING

If it is desired to mount the TV antenna in a place that makes it the
least conspicuous, it should be mounted as far to the rear of the house
as possible. Mounting it to the back wall of the house, with a mast that

Figure 7-6. Separate parts of Z-type chimney mount kit.

>
©
£
E
=
v
-
o
£
ә
2
o
i-
ч
N
`
^
o
м
3
o
W

x
Е
3
o
E

CHIMNEY FLANGE

RATCHET
BOLT HEAD

CHANNEL HOLE
RATCHET SLOT

Figure 7-8. Details of a ratchet tightening system.

places the antenna above the roof line, does this. There are several
wall mounts available, most of them based on the use of brackets with
a V or modified U-shape to them.

Wall mounts are available for clearing roof overhangs from 3 inches
to 12 inches.

Figure 7-9 shows a wall mount. The metal is 3/16 inch thick
aluminum. The two brackets are mounted one above the other to give
two-point suspension to the mast. The brackets hold the mast out six
inches from the wall.

Heavy-duty wood lag screws are all that are needed for mounting
the brackets to the side of a house using wood sheathing. Try to find
at least one of the vertical wall studs, and use screws long enough to
reach the stud. The next stud would normally be 16 inches away, too
far for the other end ofthe bracket to reach. With most homes built of
brick or stucco, wood screws must give way to lag screws. For brick
homes, it is easier to go into the mortar between the brick. For either
mortar or stucco, a hole must be drilled or pounded out and a wood or
lead insert placed in the hole. The lag screw is placed into the insert,
which expands as the screw is tightened. Holes can be made with a

Figure 7-9. А 6-inch wall mount.

carbide-tipped drill bit, or a star drill and sledge hammer. Stucco is
concrete about one inch thick. The brackets should be spaced apart
about 20% of the length of the mast used.

A sidewall bracket that avoids the need for going into brick or
stucco is the one shown in Figure 7-10. This type is wood-screwed to
the facia at the end of the house with a peaked roof. The lower
element is 48 inches long, to reach across.

Figure 7-10. Wall mount to fit facia at end of roof peak.

Mounting to the side of the house has one special advantage in
lightning protection. A ground wire can be run straight down to a rod
inthe ground, providing a short and straight run for best protection.
Figure 7-11 shows the use of a length of gas or water pipe for a mast,
run all the way down to the ground level. Here it is connected to a
ground rod with a length of solid copper wire.

MAST MOUNTING

Where greater height than can be provided with a standard five- or
ten-foot mast is required, telescoping masts in 19-, 27.5-, and 36-foot
lengths are available. Telescoping means the mast is supplied in
several sections, each with a smaller diameter, so each fits inside the
other. The mast sections are steel, galvanized protected, and with a
coating of zinc. In spite of its steel construction, the total weight of
the 36-foot mast is only 30 lbs.

Because of the greater height of masts, they must be guyed.
Guying rings are supplied with the masts, for attaching the guy
wires.

Chapter 5 on fringe area antennas covers the raising of masts.

CEMENT BLOCK —
OR PLATE

Figure 7-11. Grounding the antenna mast.
RUNNING THE LEAD-IN

The two principal types of lead-in were discussed in previous
chapters. As a review, the two types are shown in Figure 7-12. The
round, black cable (Figure 7-12B) is coaxial 75-ohm cable. The
flat-looking wire (Figure 7-12A) is 300-ohm twin lead. The coaxial
cable features the shielding of one lead with an outer lead of braided
wire. This and the fact that it is round makes it easier to run from the
antenna to the TV set; it is not affected by nearby wires or
noise producing equipment. The insulation between the inner and outer
(braided shield) conductors is made of polyfoam, one of the best dielec
trics there is.

Among the 300-ohm twin-lead wire, there are three in popular use.
The cheapest is the flat brown or clear-plastic insulated type using 22
or 24 gauge wire. This is usable for indoors where weather cannot af-
fect it. The second type is an economy foam insulated type using 22
gauge wire, but also not recommended for outdoor use. The lowest
loss type, as shown in Figure 7-12A, uses an abundance of white-foam
insulation entirely covered with a dense polyethylene jacket. The
foam and large 20-gauge wire contribute to its low-loss
characteristics.

(A) Twin-lead.

(B) Coaxial cable.
Figure 7-12. Lead-in cable.

A formerly popular shielded 300-ohm twin-lead has given way to
low-loss 75-ohm coax which is much easier to install and lower in cost.
Because TV antennas are designed for 300-ohm lead-in, and the
coaxial cable has a characteristic impedance of 75 ohms, a
transformer must be used to change from one impedance to the other.

d X. E

Figure7-13. The 300-ohm to 75-ohm transformer is supplied with a rubber
boot for outdoor use.

The same type transformer сап be used to go from 300 to 75 ohms at
the antenna and from 75 to 300 ohms at the TV set because
transformers are bidirectional. A typical transformer with its rubber
boot for covering the coax connector during outdoor use is shown in
Figure 7-13. Most modern TV sets come with a 75-ohm input so a
transformer is not needed at the input to these sets.

A typical antenna transformer installation is shown in Figure 7-14.
Notice the clip which physically secures the transformer to the rec
tangular boom. This relieves the strain from the wires connecting to
the antenna. The rubber boot is shown to the right of the coax connec-
tor where it would be before it is pushed up into place. The coax cable
must also be secured against the pull of its own weight. Provide some
extra cable as slack right at the connector. Remember, wire shrinks in
cold weather. If the coax can be looped two or three times around the
boom without being near the element feeds, this will provide good
strain relief, Don't rely on electrical tape. It will come loose and allow
the weight of the cable to pull the connection apart. Use several
strong wire ties along the boom and mast. И А

Another type of transformer uses the words, splitter, combiner,
coupler in various combinations. Transformers are reversible in use,
therefore the interchangeable names. They may be used to combine
or split.

Figure 7-14. A300-ohm to 75-ohm matching impedance transformer installed
at the antenna.

There аге two special cases when these are used. When two
antennas are installed, one for VHF and one for UHF, their leads can
be combined into one lead-in with a combiner (Figure 6-10). The
antennas fasten to the outside screw terminals, and the down lead to
the center terminals. If a 75-ohm coaxial is to be used as the down
lead, a 300-ohm to 72-ohm transformer (Figure 7-13) must be used.
At the set, the transformer shown in Figure 7-15 is used to separate
the signals from the single coaxial cable lead-in to separate VHF and
UHF TV set inputs. Also provided is a set of terminals for FM use.
Many TV sets have separate UHF and VHF input terminals.

Figure 7-15. Transformer splitter
with 75-ohm coaxial
cable input.

Figure 7-16. Indoor splitter for use with 300-ohm line input.

Figure 7-16 shows a splitter for indoor use and where 300-ohm
lead-in is used from a single combined UHF/VHF antenna. This one
is for use at the TV set for separating signals to VHF and UHF TV
set inputs, plus FM.

Figure 7-17 shows installed coax cable plugs. The rubber boot is
used for outwork only. No soldering is necessary, and the only tools
needed are a sharp knife or razor blade, wire cutters, and a crimping
tool, see Figure 7-18. The crimping tool is a cheap life-long investment
so don't attempt to do without it. You can not make proper connector
installations without it.

Figure 7-17. Closeup view of coaxial plugs.

Instructions are included with the tool and connectors, but addi-
tional points are worth mentioning. Be careful not to nick wires when
cutting insulation. Cut only part way through and then tear it the rest
of the way. A nicked wire will surely cause you trouble sooner or later.
The center conductor should extend about ув” beyond the plug.
Center insulation should end at about the inside shoulder of the plug.
Fold back the outer shield to cover the cable jacket to the back edge
of the crimp ring. This increases shield conduction to the plug
and makes removal by pulling almost impossible as the folded-back
shield has increased diameter over the rest of the cable under the
crimped ring. When bending back the RG-6/U shield and wires

Figure 7-18. Соах connector crimping tool.

carefully tear the foil back to the jacket in 3 or 4 places so that the
plug can be installed under the foil without bunching it up.

At least two types of coax cable are popular for TV, RG-59/U and
RG-6/U. The RG-6/U is lower in loss and more completely shielded so
it is preferred in most installations.

On 300-ohm twin lead, some of the insulation is stripped away from
the two wires, exposing about 3⁄4 inch of wires. Twist the wires in the
direction in which they are normally twisted in the cable, and bend a
hook on both of them. Or, for a more professional job, use crimp con-
nectors.

Both types of lead-in must be supported every few feet to prevent
their being whipped by the wind, and, in the case of the 300-ohm twin
lead, to keep it away from metals. In addition, the 300-ohm lead must
be twisted about five turns every yard. This gives equal capacity
effect exposure to any metals that may be nearby, and maintains a
balanced condition in the two wires.

STANDOFFS

Different standoffs are used for fastening to different types of
structures. The photographs that follow show them. However, the
black circular part of the insulators are all the same and are designed
totake any kind of cable. They are slotted on one side, and they turn
in the metal part that encircles and holds them. The cables are
attached by turning the insulator to where the slot is in line with the
open part ofthe metal, and the cable is forced into the center through
the slot. After the cable is in, the insulator is turned so the slot is
opposite the metal opening. This prevents the cable from coming out
of the insulator. However, the slot in the insulator is too narrow to
insert heavy cable such as coaxial and shielded 300-ohm twin lead
while bound by the metalring. For heavy cable, remove the insulator
by pressing it out, then insert the cable into the insulator, and
reinstall it into the ring of the metal holder.

The standoffs in Figure 7-19 are for mast mounting. The strap on
the standoff is of stainless steel and one end of the strap is fastened to

Figure 7-19. Standoff with straps to fasten to masts or poles.

the base of the standoff. The strap is placed around the mast and the
free end of the strap is threaded through slots in the base of the
standoff. Tightening down on the screws tightens the strap against
the mast. Another mast type standoff is shown in Figure 7-20. The
hooked part is spring steel and merely snaps onto the mast.

Figure 7-20. Snap-on standoffs are spring steel.

The standoffs in Figure 7-21 are for fastening to wood. A pilot hole
should first be drilled into the wood, to make inserting and tightening
easier. This practice is good for any wood screw. The standoffs shown
in Figure 7-22 are also for wood. They are pounded into the wood like
anail. Note the reverse bend at the top for taking the hammer blows.
A crimp on the shank a short distance from the point is used as a
depth gauge.

Figure 7-23 shows mortar-type nails as part of the standoff. Like all
“hot” nails, they have blunt ends and square shanks. They are easily
driven into the mortar between bricks and will also go through
eoncrete, with extra care. But they are primarily intended for
fastening into mortar. Use a short-handled sledge hammer and drive
them firmly but carefully. The mortar gives way and compacts
around the shank for a firm hold.

Figure 7-21. Standoff insulators using wood screws.

RUNNING LEAD-IN INDOORS

If the lead-in cannot be brought through the attic and down an
inner wall, as shown in the photo of Figure 7-24, the next best thing is
to go through the outside wall of the house. This is done by means of
a “wall tube,” as illustrated in Figure 7-25. This feed-through type of
device is all plastic, takes any kind of lead-in, and will fit walls up to
13 inches thick. It includes a rubber grommet for the outside flange,
which makes the fit weatherproof.

If the outside wall is brick, select a point at a corner of the bricks
and pound a hole through the mortar with a star drill or use an elec-
tric drill and a masonry bit. If your home is frame and veneer brick
(one thickness of brick), determine where a stud in the wall is by

Figure 7-22. Nail-in standoff insulators for wood.

means of a magnetic device to identify plaster-holding nails in the
studs. These magnetic detectors are inexpensive and may be purchas-
ed at any hardware outlet. When going through the mortar between
the brick, select a point that won't strike a stud inside. An all-brick
home will have two or more thicknesses of brick, and % inch furring
Strips between the brick and plaster walls. A masonry bit will go
through the furring strip without trouble.

Figure 7-23. Nail-in type standoff for driving into mortar.

EC
es

Figure 7-24. Coaxial cable entering an attic.

Figure 7-25. Plastic wall tube.

The inside end of the wall tube is made to accommodate the wall
socket illustrated in Figure 6-14. Thread the 300-ohm twin lead
through the wall tube, fasten it to the terminals of the socket, and
fasten the socket to the wall tube. No soldering is required.

A mating plug, supplied with the socket, is then connected to a
300-ohm twin lead long enough to reach the TV set. The plug, also,
requires no soldering. If the TV set is not near the socket, you may
find it necessary to run twin lead along the molding to the location of
the TV set. Special tacks are available to do this, and the installation
is quite inconspicuous.

If the lead-in can be brought through the attic and down inside a
wall, the installation can be much more professional looking. There is
more work involved, however. The work has to do with dropping the
cable down inside the wall.

The inside walls of homes are usually made of 2 x 4 studding with
plaster board fastened to both sides. Across the top of the studs are
one or two thicknesses of 2 x 4 called a plate. On inspection you will

see electrical conduit, or unpiped electrical cable, going through
places in the plate that are exposed in the attic. If you are using
eoaxial eable, or shielded 300-ohm line, you can thread your cable
through the same cuts in the plate as the other services, and there is
usually enough extra room to do this. For unshielded 300-ohm line
you must drill a new hole and keep the line away from any other
cables or metallic objects.

Some city codes require home construction to include firebreaks in
the walls. These are horizontal pieces of 2 x 4 set in about halfway
downthe wall. Ifthese are present in your walls, you have a problem.
The only way to go through these firebreak pieces is to drop a
weighted string down the hole in the plate and estimate the distance
down for the firebreak piece. Then, chop some plaster away inside
the room at the point where the firebreak is, notch the wood to allow
the cable to go around it, and replaster and repaint the wall.

Homes with basements or crawl spaces under them can use the
method described above, but working up from the space beneath,
through the sill on which the studs rest. The sill is similar in
construction to the plate mentioned. Where firebreaks are used in
walls, working from a crawl space or basement beneath avoids the
problem, as it is only necessary to go about a foot above the molding.

The lead-in may be brought through a wall by cutting a small hole
just large enough to accommodate the cable. Estimate the entrance

to be as near to your TV set as possible. A preferable method is to
install an electrical box and use a socket wall plate. Electrical boxes
are available for support by the plaster itself, as well as by nailing to
studs.
If you are planning on building, or are in the process of building a
new home, the time to put in TV cables is when the house is fully
framed, but before the plaster walls have been installed. The work of
running cable in the wall is very easy at that time.

WALL MOUNTING SOCKETS

А neat indoor lead-in installation is the end result when cables are
runinthe wall and terminated in a wall mounting socket. The finished
look is like that of an AC outlet of your house wiring system. Figure
7-26 shows several plates available. Some fit the standard electrical
outlet boxes, as mentioned above. Others are made for surface
mounting onto the wall, and no box is needed behind them. Some are
made to accommodate a matching plug, for use with one 300-ohm
twin line. Another has two sets of terminal holes for taking two plugs,
for use either when two separate antennas and lines are used, one for
` УНЕ and one for UHF, or for a single line with a splitter mounted
behind the plate. Some plates have terminal combinations for

Figure 7-26. Different types of wall €
plates.

connecting a TV set and a multicable line to a rotor. Matching plugs
are available for both. There is also shown a plate that is used with
coaxial cable. The type of plug shown in Figure 7-17 screws into this

receptacle.

СНАРТЕК 8

INDOOR TV ANTENNAS

Itisalong road from the days of the simple rabbit ear antenna for
indoor use, to today’s multiple-tuned indoor antenna. Time was when
the only TV stations on the air were in Channels 2 to 13, the VHF
section of TV channels. And before the days of color TV, the simple
rabbit ear shown in Figure 8-1 with its telescoping elements did a
pretty good job in locations where outdoor antennas were impossible.
Sliding the elements in and out tuned the antenna to the channels in
use. Today these are probably used more for FM than TV reception.

DESIGN FOR TODAY'S TV

The evolution in the design of indoor antennas for TV follows the
evolution of the increased service offered by TV. When UHF
channels came into use, the simple rabbit ears were not adequate.
The elements were too long to resonate at the much higher channel
frequencies. The rabbit ears were maintained for the VHF section of
the band, but elements were added for UHF. Figure 8-2 illustrates
one of the simplest of these. The large hairpin shaped element in the
center was made tunable by a front knob.

Figure 8-8 shows another indoor antenna for TV. It looks similar to
those described above, but has improvements over them, The VHE
elements and UHF loops are mounted on a rotating turntable which
revolves without turning the entire base. It has a phasing switeh to
help reduce “ghosts” on the TV screen, plus a switch for selecting
optimum results for VHF, FM, or UHF.

Figure 8-4 has a rotating ОНЕ double loop section, and
four-section VHF rods. The rotating UHF section permits orientat-

Figure 8-1. Budget VHF Antenna. Figure 8-2. Standard UHF/VHF Antenna.

ing the direction for reducing reflections which can cause “ghosting.”
An added phasing switch allows for better tuning and impedance
matching.

THE FINEST INDOOR TV ANTENNA

The best of indoor TV antennas is shown in Figure 3-1. Flexibility
of controls results in an ability to adjust for optimum reception when

Figure 8-3. Indoor antenna with a Figure 8-4. Indoor antenna with ro-
rotating turntable. tating UHF section.

the use of an indoor antenna becomes the only option. The antenna
elements can be turned separately from the base by one knob.
Another knob controls a 12-position switch for phasing against reflec-
tions in the VHF range.

Having purchased an indoor antenna it is wise to do some
experimenting for best results. Experiment with locations in the
room. The top of the TV set might seem to be the most convenient
place for the antenna, but it is not necessarily the best place. An
outdoor antenna has high forward directivity and reduces the
possibility of "ghosts" or secondary images. An indoor antenna does
not have this quality. Ghosts may be introduced by the return bounce
of a secondary path signal from metallie objects in the room. If you
encounter ghosts in the pieture, move the antenna to another
location. Try another, and still another. Find the spot that gives you
the fewest ghosts, and the best hold to color pictures.

FM INDOOR ANTENNAS

Like TV, the best reception on an FM tuner or receiver is from an
outdoor antenna. Next best is from a two-set coupler connected to a
TV antenna, where the coupler feeds the TV set and the FM tuner.

The frequency range of the ЕМ band is 88 to 108 MHz. Being only
20 MHz wide, it does not compare with the broad frequency spectrum
of TV. For this reason many FM tuners are supplied with an indoor
dipole made of 300-ohm twin line, like the one described in the
chapter on FM antennas. While they work quite well they still cannot
cover the full 20-MHz frequency width with equal response across
the entire band. Nor can they be turned for best pickup if FM stations
are in different directions, which is generally the case. The FM indoor
antenna shown in Figure 8-5, overcomes the two shortcomings
mentioned above. The telescoping elements and tuned coil in the
center provide precise tuning to the frequency to be received. In
addition, the antenna can be turned on its base for best directivity.

As in the case of the color-TV reception, a stereo signal requires
the reception of a much stronger signal for the multiplex control
carrier to give good stereo separation. A tunable indoor antenna,
such as this one, can give good stereo reception, short of an outdoor
antenna.

For those who want to make their own indoor FM antenna, the
sketch of Figure 8-6 shows the details. A piece of 300-ohm twin lead is
all you need. It is also obtainable ready-made from Radio Shack. This
antenna can be tacked behind the hi-fi cabinet, but results are better if
it can be installed up higher, such as along the picture molding near

Figure 8-5. FM Stereo Antenna.

p 5 FEET

STRIP INSULATION TWIST
WIRE ENDS TOGETHER

CUT ONE WIRE ONLY AT
CENTER AND SPLICE TO
LENGTH OF LEAD-IN

... TO FM TUNER

Figure 8-6. An FM antenna you can make from 300-ohm twin-lead.

the ceiling. Its position should be broadside to the path or direction of
the principal FM station you want to receive.

CHAPTER 9

INSTALLING A ROTATOR

There are a number of advantages in using a rotator for a TV
antenna. In fringe area reception, where the location may be
between two cities with TV service, the advantage of being able to
turn the TV antenna in the direction of either city is an obvious one.
In such fringe area locations, no antenna installation should be
contemplated without including a rotator.

Even in close-in metropolitan or suburban areas, there may be an
advantage to the use of a rotator, depending on circumstances. In
some cities not all TV stations are located in the same place. While
the practice is for all stations to work together and all place their
antennas on a single high point, this practice is not universal. Where
this is not the case, the use of a rotator is a necessity, if best reception
is desired from all stations.

Whether all TV station antennas are in the same place or not, there
is almost always the problem of secondary paths, which results in
ghosts in the picture. A highly directional receiving antenna should
eliminate or substantially reduce the strength of the secondary path
signal. But where this is not possible, a rotator can be the answer. A
rotator can orient your antenna just enough in one direction or the
other to turn it away from the secondary path signal, yet not lose
enough primary path signal strength to affect the reception. The
proper use of a rotator may completely eliminate the ghost.

FM station antennas are hardly ever located in one place. If FM
reception is as important to you as the reception of TV, include а
rotator in your installation if for no other purpose than to turn your
TV antenna (it is assumed you are feeding both TV and FM tuner
from the same antenna) in the direction of the FM transmitting
antenna location. This is important to the best reception of stereo

MANUAL AND AUTOMATIC ROTATORS

There are two basie types of rotator systems, manual and
automatic. Each system consists of a rotating mechanism with an
electric motor and reduction gears in a weatherproof housing, and a
control box and indicator. The mechanism is located on top of the
mast, and the antenna is mounted above it. The indicator is located in
the house, on or near the TV set. A three-, four-, or five-wire cable
connects the two.

On manual rotator systems, the indicator has a lever or switch and
a meter marked with compass points instead of numbers. The lever
or switch is pressed in one direction or the other and held while
watching the meter. When the needle on the meter shows the
direction you want, the lever is released. On the Archerotor, a knob
on the control box is set to the direction desired and the antenna
follows automatically, see Figure 9-1. A moving indicator tells you
when the antenna is pointed in the right direction.

The rotator shown in Figure 9-2 uses mechanical braking to hold
the mechanism in its stopped position. The mechanism is held in a
fixed position to the lower mast with two sets of bolts and serrated
clamps. The bearings are fully weatherproof and lubricated for life.
The control box contains the control dial and solid-state circuitry for

Figure 9-1. The control for the Archerotor.

Figure 9-2. Archerotor rotator.

handling the control of the motor. The antenna may be turned in
either direction but never more than a complete 360? circle. It uses a
three-wire control cable.

RUNNING THE CONTROL CABLE

The control cable may be dressed close to the mast and tied to it at
intervals down its length. No special precautions are required to keep
this cable away from metallic objects (except 300-ohm unshielded
twin line). If the antenna cable is coaxial or if the 300-ohm cable is
shielded, the control cable may be brought down and into the house
along with, and parallel to, the shielded antenna cable. They may be
tied together with wire ties if that is convenient.

The unshielded, ribbon-like, 300-ohm twin line must not be run
near the control cable, or any other cable or metallic material. This
type of antenna lead-in must be brought down the mast using
mast-mounted standoff insulators and carried down and into the
house as described before.

ORIENTATING FOR DIRECTION

It is obvious that the antenna must point in the direction to which
the control knob has been set. This is easy to achieve.

With the control unit wired to the cable, and the antenna and rotor
installed, set the control knob to north. Return to the antenna
installation and loosen either the bolts to the antenna or the bolts
holding the rotor to the lower mast. Turn one or the other to point to
the north, and retighten all bolts.

CAUTION. The antenna lead-in cable must be given enough slack
to allow the antenna to turn through a half-circle (180°) in either
direction. The rotator does not turn the antenna continuously, but
through a circle of 360? and back again. By securing the antenna
lead-in at the half-circle point, only a half-circle slack need be
allowed.

With the antenna turned to point south, fasten the standoff
insulators on the south side of the mast. Allow a loop of cable above
the highest mounted standoff, leaving a generous amount of slack. As
the antenna rotates to the north in either direction, the slack will be
taken up, although it should not pull tight, Figure 9-3 shows how to
do this.

TV LEAD-IN
SLACK

Figure 9-3. TV antenna installation
with rotator.

CHAPTER 10

TV INTERFERENCE AND WHAT TO DO
ABOUT IT

Interference as it is defined here is that which occurs outside of
your TV set. It does not include rolling pictures or other out-of-sync
problems in your set or at the TV transmitter. But there are forms of
interference which can spoil a good picture and frequently something
ean be done about it.

There are many sources of radio waves which fall partly in the
frequency of a TV channel, and ride into your set along with the TV
signals. Most originate from sources very close by and frequently can

betreated with some form of filter connected to the TV lead-in. Some
cannot be cured.

SNOW

This type of interference actually looks like it is snowing on the
Screen when you are watching a program. The weaker the TV signal
the heavier the snow appears. To overcome this you must build up
the signal strength. This is done by using a better antenna, mounted
outdoors as high as possible. The antenna requirements for fringe
area reception were covered in Chapter 5.

GHOSTS

Another problem that must be included in the definition of
interference from external sources is "ghosting." This and its
solution were covered before as it, also, is something you can control.
The solution is the selection of a highly directive antenna and its
proper orientation. See Chapter 3 for more details.

INTERFERENCE FILTERS

The kinds of interference mentioned above cannot be reduced by
adding gadgets or special devices to your TV system. There are
forms of interference that can be reduced by the use of a device called
a filter. A filter is a tuned circuit of capacitors and inductors designed
to pass radio frequencies within the TV bands and reject all those
below or above it. In technical parlance these are called bandpass
filters. Other types pass frequencies above a certain frequency and
reject all others below that value. They are called highpass filters.
And then there is the simple capacitor which, depending on its value,
acts like a short circuit to high radio frequencies, while not affecting
very low frequencies. Filters are used to reduce or eliminate the type
of interference described below, except fluttering.

SPARKING

A most annoying type of interference is that resulting from
sparking in electrical equipment (Figure 10-1). Such sparking can
come from the brushes of universal type motors, such as those used
for circular hand saws, electric drills, sewing machine motors, etc. It
will look like a series of white dots in horizontal lines across the TV
Screen.

Interference of this type described as sparking may enter the TV
set in one or both of two ways. It may be picked up by the AC line
feeding power to the set, or it may be picked up by the antenna,
whichever is closest to the source of interference. A filter may be

Figure 10-1. Interference caused by sparking.

used at either or both points, that will bypass all or most ofthe spark
pickup and keep it from getting into the TV set. Figure 10-2 is an
antenna-type filter. For use, the antenna lead-in is disconnected from
the back of the TV set, and the two leads ofthe filter are connected to
the TV terminals. The lead-in is connected to the pair of screw
terminals on the filter. Within the filter is a bandpass circuit that
blocks out all radio frequencies above and below the TV frequencies,
but allows TV frequencies to pass through. Since interference
sparking is at radio frequencies, those that fall within the TV
frequencies will get through. However, quite a bit of the spark
interference will be blocked, with a resulting decrease in interfer-
ence.

The best way to reduce sparking interference is at the source.
There are bypass capacitors which can be connected across motor
brushes and other sparking devices to short-circuit the sparking. But
this requires knowing the equipment and what value capacitor to use,
and is best left to a professional to do.

TV
INTERFERENCE
FILTER

ARCHER
Cat. #15-582

Figure 10-2. An interference filter
which connects between the lead-in
and the TV set.

THE HERRINGBONE PATTERN

Figure 10-3 shows a typical herringbone pattern across the TV
Screen. It is caused by other transmitter services, notably the
Citizens band (CB), and to a lesser degree amateur radio operators
(hams) who are using their radio transmitting equipment.

There are over 10 million CBers in the country and one or more are
undoubtedly near you; that is, within a block or two. Their frequency
of operation is between 27 and 28 MHz. CB interference is caused by
harmonics of the transmitting frequency falling into a TV channel. A
harmonic is а multiple of the basic frequency.

^na E ii i T7 LÀ
ЧТ
: PPITIN ALl ierni

Figure 10-3. Herringbone pattern caused by CB transmitter radiation.

Nothing can be done at the TV set to keep harmonic interference
out. The best you can do, if you can determine who the offender is, is
to request (but you cannot demand) that he observe silent hours
during your favorite program, or suggest he add a lowpass filter to
his equipment. This filter will reduce the harmonics from his
transmitter.

When a CB or other transmitter is very close to you, even the
fundamental frequency can cause interference by what is called
swamping. In this case the very closeness can produce enough power
to get through your set. There are two filters you can add into your
antenna lead-in to reduce and sometimes eliminate this. Figure 10-4
shows a filter which connects directly to the terminals of your ТУ set.
A more effective filter is shown in Figure 10-5. This one connects in
series with your antenna lead-in. That is, you connect the antenna
lead-in to the connector at one end of the filter, and the short lead
from the other end of the filter to your set.

Figure 10-4. A trap-type filter for connecting across the antenna terminals.

Amateur radio stations can also cause the same kind of
interference mentioned above. There are only about 250,000 licensed
кш stations, but they generally run higher power than the

Bers.

Amateur stations are less of a problem for two reasons. For one,
nearly all amateurs use a low-pass filter at the output of their
transmitter to keep harmonic radiation down. And, number two, you
will usually find them very cooperative in working with you to do
something about any interfering problem. Again, remember, they
are licensed by the Federal Government to operate a transmitter and
demands to stay off the air will get you nowhere. A friendly request
for assistance will get you a friendly response.

Figure 10-5. А deluxe high-pass filter.

PICTURE FLUTTER

Airplanes flying overhead, especially to or from the direction from
which the signal is being received, frequently cause the picture to
flutter. That is, the picture will get brighter and dimmer in cycles of
about three to fifteen times a second. This is the result of signal
reflections from the metal of the airplane. It is a secondary path
signal similar to that mentioned in an earlier chapter. Because of the
movement of the airplane the secondary path signal will arrive in
phase and out of phase with the direct signal. Thus the signals
sometimes add and sometimes subtract from the level of the original
path signal. The effect is especially noticeable when indoor antennas
are used.

To avoid or reduce flutter the same high directivity of antenna
mentioned earlier to reduce ghosts is required. This narrows the
beam of signal acceptance thus increasing the strength ofthe original
path signal, and reduces the strength of the secondary path signal
from the airplane.

CHAPTER 11

CB ANTENNAS

All antennas must meet certain basic requirements, but transmit-
ting antennas are more critical as to the matching of impedance
between the feed line and the antenna. This match is indicated by the
amount of Voltage Standing-Wave Ratio (VSWR and often shortened
to SWR) on the transmission line. Ideally the VSWR should be unity
(one-to-one), indicating a perfect impedance match. Just about any
length of wire can be used for receiving AM, FM, TV, CB, etc., but
the impedance of an incorrect length of antenna could cause a CB
transmitter to malfunction and not deliver its power to the
antenna. The narrow frequency band of the 40 CB channels covers
only 0.44 MHz (26.965 to 27.405 MHz) compared with the 20 MHz of
the FM band, 34 MHz of the low VHF TV band, and 42 MHz of the
high VHF TV band. For this reason, simple-looking antennas can be
designed to provide an acceptable impedance match between antenna
and feed line over the entire CB band.

It is conventional for CB to use vertically-polarized radio waves.
This dictates vertically oriented elements, resulting in omnidirec-
tional radiation patterns when single-element whip antennas are used.
This is ideal for communicating to all directions. Recall from Chapter
4 that a horizontally polarized antenna as used for FM becomes more
complicated to obtain an omnidirectional pattern.

To obtain maximum radiation in the horizontal direction, you
would think that the higher (longer) the vertical antenna is made, the
greater the horizontal radiated signal strength, but this is not the
case. Assuming a perfect ground, as the vertical whip is increased in
height, signal does increase in strength until the electrical height of
about $ wave length is reached, and then signal strength starts to
decrease drastically in the horizontal plane and increase vertically
above the antenna.

To complicate matters, we usually don't have a "perfect ground" so
we use three or four ground radials at the base of the whip and elevate
the entire system as high as possible (or legal) above undesirable
ground and other objects, see Figure 11-1. These ground radials per-
form three very important functions: operate in conjunction with the
whip (antenna) section to obtain resonance in the CB band, electri-
cally decouple the mast from the antenna so that the mast and whip
don't act together as an antenna higher than 5% wavelength (which
would cause most of the RF energy to be directed vertically over the
antenna), and thirdly, help to provide a feedpoint impedance as close
to 50 ohms as possible.

ANTENNA LENGTHS AND IMPEDANCE MATCHING

A signal wavelength in free space is equal to the velocity of propa-
gation in meters-per-second (300 million/second) divided by the fre-
quency in cycles-per-second or hertz (27.2 MHz for the center of the
CB band). The CB wavelength is therefore about 11 meters. From
this we can determine the expected lengths for antennas having the
typical 1⁄4 wave (or less) to % wave. A quarter-wave antenna is about
2.75 meters (9 feet), a half-wave about 5.5 meters (18 feet), and a %
wave about 6.9 meters (22.6 feet). These lengths are for a theoretical
antenna of negligible wire diameter, but indicates to us that to obtain
a reasonable antenna height some engineering must be done.

Only two antenna heights within the range of Ув wavelength will
give us a pure resistive feed-point impedance without some form of
loading coil or transformer, % wave and V? wave. And, of these two,
only the М wave presents an impedance near the 50 ohms which is
common for coaxial cable. Therefore, only '4-wave antennas can be
made without loading coils or matching transformers for direct
feeding with 50-ohm coax, and then only with proper ground-plane
construction.

The theoretical feed-point impedance of a quarter-wave antenna
with horizontal ground-plane elements is about 36 ohms; and that of a
half-wave dipole in free space is about 73 ohms. Design engineers are
therefore able to obtain a 50-ohm feed impedance by proper choice of
the ground radial angle somewhere between horizontal and vertical
(downward) on quarter-wave antennas, see Figure 11-1. Other factors
which affect the feed-point impedance are the length of all antenna
elements and the presence of a matching or loading coil. The feed-
point is always at the junction of the vertical radiator and the ground-
plane elements. The vertical radiator is connected to the coax cable
center conductor and the ground elements to both the mast and cable
shield. This allows the mast and cable shield to be well grounded to
earth for better lightning protection.

М WAVE

Figure 11-1. Basic quarter-wave EX
КУ

ground-plane antenna. FEED POINT 50 2

АЙ other antenna lengths require the use of a top capacity hat, a
center loading coil, or a base loading coil or transformer to obtain a
feed impedance of 50 ohms and resonance of the antenna system.
Some whips are constructed with what might be called a distributed
loading coil. Wire is wound around a fiberglass core the entire length
of the whip and then completely covered with a thick layer of
fiberglass to provide added strength and insulation. This type con-
struction gives better durability, improved radiation efficiency, and
some protection should the antenna accidently come into contact with
a power line.

Coaxial cable is always used for the feedline, and the same com-
ments apply for CB antenna work as for TV. That is, use as low a loss
cable as you can afford when more than a few feet are needed or you
willlose a great amount of the already-low transmitter power (4 watts
maximum) in the cable. At the frequencies used for CB, around 27
MHz, the size of the cable is more important than the type of insula-
tion. For example, small RG-58/U cable typically has a loss about
twice that of the larger RG-8U. The loss difference between either
cable having the same center conductor size but foam insulation in
place of solid insulation is negligible. This, of course, differs from that
at the upper VHF and UHF TV frequencies where the insulation has
a big factor. An RG-58/U coax is typically used for runs of 25 feet or

less, such as in mobile installations, and RG-8/U is used for all longer
runs.

QUARTER-WAVE GROUND-PLANE ANTENNA

This type antenna is identified by a simple vertical whip section
about 9 feet high and having three or four ground radials of about the
same length as illustrated in Figure 11-1. Direct impedance matching
to the 50-ohm coaxial cable is very good when ground radials are

sloped downward at an appropriate angle, usually about 45°. This
eliminates the need for any kind of impedance matching device, which
tends to restrict bandwith and inject signal loss. The whip and
ground radials are simply connected to an SO-239 type connector
which receives the standard PL-259 type plug used on 50-ohm coaxial
cable. Cable may be purchased with these plugs already installed,
simplifying installation. Sloped radials are also effective for maintain-
ing maximum radiation in the horizontal plane, as opposed to horizon-
tal radiators which tilt the radiation upward toward the sky.

HALF-WAVE GROUND-PLANE ANTENNA

A full-size half-wave ground-plane antenna may be identified by
both its height of about 18 feet and the bulky matching network at its
base. The matching network may take on various physical forms, but
its function is always that of changing the impedance at the base of
the half-wave whip from a few thousand ohms to the 50 ohms
required for coaxial cable.

A half-wave antenna doesn't require ground radials to complete its
resonant operation as does a quarter-wave antenna, but something is
still needed to complete the feed impedance connection for the coax,
and decouple the mast from operating as an extension of the antenna.
Therefore, ground radials or a quarter-wave decoupling sleeve is still
required to keep the entire mast and coaxial cable from acting as the
antenna. A properly-constructed half-wave ground-plane antenna is
capable of producing a gain of up to 1.67 dB over a properly-
constructed full-sized quarter-wave one. This is a power increase of
about 1.5 times. .

The desire to produce an antenna with higher gain than the simple
quarter-wave type has resulted in a shortened form of this antenna.
Various methods have been used such as center loading coils, base
loading coils, distributed loading coils, and top capacity hats. Figure
11-2 shows a shortened whip that uses a top capacity hat. Antennas
which are shortened severely do not provide significant gain over a
well-designed full-size quarter-wave antenna. This is due to both the
decreased radiating-element length and matching network losses.

% -WAVE AND 0.64-WAVE ANTENNAS

The highest gain is possible with a properly-designed antenna in the
Ув to 0.64 wavelength, but as with the V2-wave type, any attempt to
shorten the antenna or skimp on the decoupling of RF currents from
the mast and coax by reducing or eliminating ground radials or
decoupling sleeves defeats the purpose of going to these larger
antennas. A $4-wave antenna having double '4-wave decoupling

Figure 11-2. A shortened whip
utilizing top-hat loading.

sleeves is capable of the highest gain in this type antenna, but this
type has not gained popularity in CB. A popular marine radio
antenna using this construction has a 3 dB (2 times power) gain over a
typical /2-wave ground-plane antenna.

COAXIAL ANTENNA

A decoupling sleeve as just mentioned is illustrated in Figure 11-3.
Construction and characteristics are varied enough from the ground-
plane antenna shown in Figure 11-1 that a different name is applied to
this type antenna, the coaxial antenna. The name comes from the fact
that the lower part of the antenna is made up of a sleeve which is 3 to
10 times larger in diameter than the coaxial cable and is coaxial to it.
This sleeve is connected to the cable shield at its top, where the center
conductor also connects to the top whip, and is then insulated from
everything over its entire length. All three radial requirements are
efficiently provided by this type construction. The quarter-wave whip
and quarter-wave sleeve work together as an effective half-wave reso-
nant vertical antenna (even though this is commonly called a quarter-
wave coaxial antenna due to the whip length length). The coaxial
cable outer shield and inside surface of the sleeve form a decoupling

'4 WAVE "-

ELEMENT

CONNECTION

М WAVE SLEEVE HERE

Figure 11-3. A quarter-wave coaxial-
type antenna uses a sleeve to replace
the radials.

ELECTRICALLY

Cc
OAXIAL CABLE OPEN END

stub which makes the RF see a very high impedance at the open end
of the sleeve. This effectively decouples the coaxial cable and mast
from acting as part of the antenna. The thickness (diameter) of the
whip and sleeve tends to lower the feed impedance of this half-wave
system from the theoretical 73 ohms of the infinitely-thin free-space
half-wave reference antenna to the 50-ohm impedance of the coaxial
cable. The use of any poor matching system is therefore eliminated.

With the advent of the law requiring base station omnidirectional
antennas to tolerate a fall against a power line (see LAWS AFFEC-
TING CB ANTENNAS at the end of this chapter), this coaxial type
antenna using fiberglass construction will probably become the most
common type omnidirectional base station antenna. Figure 11-4
illustrates a base station coaxial antenna. The quarter-wave whip and
quarter-wave sleeve give a total height of approximately 16 feet. This
full-size antenna complies with the newly enacted law.

INDOOR CB ANTENNA

There is a CB antenna designed for indoor use. It is made a
half-wave in electrical length by the use of a fiberglass rod with
antenna wire helically wound around it. The top section adjusts from
ТУ feet to 8% feet. It is supplied with seven feet of coaxial cable
connected, and ending with a PL 259 plug. All you need do is set it up

Figure 11-4. Omnidirectional base
station coaxial antenna.

in the corner of the room and plug it into the CB transceiver. Adjust
the top section for best performance.

One must not expect the same results from this antenna as from an
antenna mounted outdoors at a greater height, and with full-sized
dimensions. But lacking that possibility, such as in an apartment, this
antenna will give surprisingly good performance.

BEAM ANTENNA

Talk to any amateur radio man and he will tell you, when physical
dimensions permit, his most effective antenna is a beam antenna.
This is a type of construction similar to that described for TV
antennas earlier in this book, but with a higher efficiency due to the
much narrower bandwidth over which they operate. The increased
forward gain and the higher front-to-back ratio results in an effective
power gain many times that of a standard half-wave antenna.

The 3-element beam for CB is like an amateur radio beam except
forhaving its elements in a vertical position instead of horizontal. The

center element is the one the coaxial line is connected to. The long
element to one side is the reflector, and the short element on the
other side is a director.

The maximum forward gain, the designation for power increase in
the forward direction, is almost 9 dB, making a 4-watt output as good
as a 32-watt output from a half-wave only antenna. The front-to-back
ratio refers to the difference between the front of the antenna to the
back of the antenna in output or receiving sensitivity. This ratio is
approximately 25 dB, which is a mathematical ratio of 300 to 1.
Theoretically, a station at a given distance behind you would have to
have 300 times the power of a station the same distance in front of
you to be equal in received loudness.

But, for effective use of a beam it must be capable of being turned
to the direction of the station with which you are communicating.
This calls for the use of a rotator, and both antenna and rotor installed
on a mast. The same rotator used for TV may be used for CB. See

Chapter 9.

CUBICAL QUAD ANTENNAS

Another very directional beam antenna which is popular in
amateur radio and adapted to CB is the cubical quad antenna. This is
generally used in a modified version where the driven element is a ver-
tical whip (or whips), but the director(s) and reflector are loops of wire
near one wavelength in circumference. This type antenna can be made
using light but strong fiberglass poles and small size wire so that the
weight of this massive-looking antenna is actually less than many
Yagi-type beam antennas. The problem arises when an ice storm
causes excessive weight which is too much for the boom or cross
members to support. The gain and front-to-back ratio of a three
element quad antenna rivals that of a Yagi-type beam of three or four
elements.

MOBILE ANTENNAS

The greatest feature in operating Citizens band is the ability to
communicate from a moving vehicle, at a small investment in equip-
ment. Most CB transceivers today use solid-state circuitry, are small,
and are easily mounted under the dash of a car. All that is necessary
is to mount an antenna and connect it.

Most CB mobile antennas are pretty much alike, differing only in
details. The similarity lies in the use of a quarter-wave vertical
element, with the car body acting as the other quarter-wave, for a
half-wave theoretical antenna. They differ in the method of
mounting, in general construction, and in the use of loading coils in
eases to reduce the length of the vertical element.

The first consideration in the selection of a mobile antenna is to
decide where it is to be mounted on the car. The best place electrically
is on top of the car roof. This results in the best omnidirectional
pattern because the mass of the car body is evenly distributed under
theantenna. The drawback in roof mounting is the total height above
the car, which might interfere with underpasses or garage entries.
Shown in Figure 11-5 is the Archer "Shorty" roof antenna. It has a coil
in the center which adds inductance to the antenna and makes it
possible to reduce the physical length while maintaining resonance.
This antenna is only 18 inches high. It has a spring at the base to
allow the antenna to bend if it hits an obstruction. It requires drilling
a 3% inch hole in the roof of the car and running the lead-in behind the
roof upholstering, like the wiring to the dome light. The antenna
snaps into its mount, so it may be quickly removed for entering a
garage or for clearing other overhead obstructions. Another roof-
mount antenna is shown in Figure 11-6.This antenna is made of
fiberglass with wire inside, and includes a coil at the bottom called a
base-loading coil, to reduce the length of the whip yet retaining an
electrical quarter-wave size. Fiberglass is quite flexible.

Figure 11-5. The "Shorty" roof- Figure 11-6. A fiberglass roof-mount
mount antenna. antenna, with loading coil.

One favorite place to mount a mobile CB antenna is on the trunk
lid. Most trunk-mount antennas are designed to be mounted without
drilling holes in the metal. The mount clamps around the edge of the
lid, or uses a powerful magnet to hold the mount to the metal.

Trunk mount antennas include a coil at the bottom of the antenna
element to maintain the quarter-wave length electrically, while per-
mitting the use of a shorter radiating element. Also at the bottom,
just below the loading coil, is a steel spring. This permits the antenna
to bend if an obstruction is hit.

Figure 11-7 shows a magnetic-mount type of antenna. The powerful
magnet at the base holds the antenna in position even at high car

. The antenna element is stainless steel.

Figure 11-8 shows а nc-hole, trunk-grip antenna. The top and bot-
tom gripping parts are gasketted to avoid marring the car paint.
Figure 11-9 is similar to Figure 11-8, but with the whip made of
graphite. It is stiffer than fiberglass but more flexible than stainless
steel.

Figure 11-7. A magnetic-mount type Figure 11-8. A no-hole, trunk-grip
antenna. antenna.

rreecae.
III ва
qu

i ——

ile

V
®

Pat
23
ved

rN um - r

Figure 11-9. A no-hole mount with

Figure 11-10. A full-length whip ona
a graphite whip.

spring body mount.

Figure 11-10 is an example of a body-mount antenna. This antenna
mounts at the side of a fender cowl or truck body. It is a full 102 inch
stainless steel whip. To mount it holes must be drilled. The swivel
ball joint permits adjusting the antenna position.

Bumper-mounted antennas eliminate drilling into the car's sheet

metal. Furthermore, the full quarter-wave length of whip is possible
(Figure 11-11).

CB/FM/AM DISGUISE ANTENNAS

The following three antennas are designed to provide two features.
They are made to look like a standard fender-mount antenna for AM
radio use, thus reducing the temptation for theft. In addition, they
include a specially designed splitter transformer which supplies
signals separately to the car radio and to the CB rig.

1————————— A)

Figure 11-11. A bumper-mount Figure 11-12. A 108-inch whip de-
antenna. signed to mount in hole for standard
mount AM antenna.

Figure 11-12 has a stainless steel whip and mounts through a
standard car antenna mounting hole. A splitter with separate leads
and plugs divides the signal between FM/AM and CB use.

CB antennas for long-haul trucks are usually mounted to their
West Coast style mirror. The one shown in Figure 11-13 has a special
clamp for mirror mounting. It is center-loaded so the whip is shorter
than the usual quarter-wave length.

Figure 11-14 shows a dual-antenna system which provides some
directivity. With one antenna on each side of the cab, and connected
together through a phasing harness, directivity forward and to the
rear is emphasized.

Figure 11-13. Single antenna for
mounting to truck mirror.

Figure 11-15 shows a gutter-clamp CB antenna. It is i
temporary installation. The antenna clamps to the e ak ы
at either front door, and the cable is brought in through the wind a
to the CB rig. dii

LAWS AFFECTING CB ANTENNAS

Al CB stations are required by law to have o
the Federal Communications Commission yc Ed e
rules are published periodically by the U.S. Government Printing
Office, for sale through the Superintendent of Documents, US
Government Printing Office, Washington, D.C. 20402 for ‘abo t
$4.50. Changes to the CB rules first appear in the Federal Regi с
тсе? publications, such as this antenna book. кее
The latest law affects the manufacture of omnidirecti
station antennas. This new law was not instituted by the ROC Bae
the Consumer Product Safety Commission. In an attempt to клы
Ше accidental deaths from contact with power lines by CB e
station whip antennas during their installation or removal, the Com.

Figure 11-14. Dual truck CB antenna gives directivity.

[

| Figure 11-15. A gutter-clamp
mount CB antenna.

mission has ruled certain type construction and tests be followed on
these antennas. As a CB antenna installer, you will be affected most
by the decreased choice of omnidirectional antenna types available
and by the increased cost of the antennas which must comply with
this new rule. Antennas manufactured or imported before the institu-
tion of this rule on February 25, 1983, may still be purchased. All
complying antennas will be of heavier and insulated construction, and
will be in cartons containing the necessary certificate of compliance.
Directional antennas escaped this ruling because of the complexity of
trying to make these multi-element antennas relatively safe around a
14,000-volt power line. No law or material construction can give you
complete safety around power lines so the best rule might be STAY
CLEAR OF ALL POWER LINES BY A DISTANCE AT LEAST
TWICE YOUR ANTENNA HEIGHT.

A long-standing law which does affect you directly concerns the
maximum height allowed for a CB antenna. Rule No. 18 states, in ef-
fect: Fixed station antennas may be no more than 20 feet above the
highest point of the building or tree on which it is mounted, or no
more than 60 feet above the ground. If you live near an airport, you
may have to obey additional restrictions. You may contact the FCC
for a worksheet to help you figure your maximum height in this situa-
tion. Your CB rules give some good illustrations which we need not
repeat here.

CHAPTER 12

INSTALLING FIXED-STATION CB
ANTENNAS

Class D Citizens band communication takes place in the 27 MHz
band. At this comparatively low frequency, radio waves can be
radiated in two ways. One is the sky wave. Radio waves are radiated
out at an upward angle and are reflected down by the ionosphere.
Sky-wave signals can reach out several thousands of miles (Figure
12-1). Communication by the sky wave is illegal to CB equipment
users.

The other form is the ground wave, which is radiation almost
parallel to the plane ofthe earth's surface. This is like the radiation of
TV signals at the higher frequencies described in earlier chapters of
this book. The communication path for the ground wave is almost
line-of-sight (Figure 12-2).

Figure 12-1. Sky-wave communication.

Figure 12-2. Ground-wave communication.

Since communication is limited to ground-wave radiation, it
becomes necessary to try to accomplish two conditions. That is, use
the highest possible gain antenna, and mount it as high as possible. If
communication over short distances meets requirements, it is not
necessary to use great heights. But the higher the antenna, the
farther out is the horizon, and the greater the distance of
communication.

Since Citizens band communication is available to every citizen of
the United States, without examination, the FCC felt some limits
must be placed on communication range to reduce as much as possible
interference between stations. This was in anticipation of millions of
stations coming on the air, a forecast that was realized. The limits are
tothe power of the transmitter (four watts output), and the height of
the antenna.

HEIGHT

FCC regulations limit the height of a CB antenna to one or the
other of the following: It must not be more than 20 feet above the
highest point of the building or tree on which it is mounted. It must
not be more than 60 feet above ground. This refers to the top of the
antenna. If a 50-foot mast installed at ground level gives you greater
overall height than mounting the antenna on your house, you may
use the mast.

For a business with offices in a multi-story building even the
20-foot limit offers excellent opportunities for a high antenna, with
excellent coverage possibilities.

While the use of a tall building for an antenna offers the advantage
of height, there are some offsetting disadvantages that must be
considered. All feed lines have some losses, some more than others.
If the transmitter is far from the antenna, on the first floor of a
10-story building for example, the losses could be considerable. The
most popular type of feedline cable for base stations is type RG-8/U, a
heavy-duty coaxial cable, 0.4 inch in diameter. This cable has a loss
factor of 1 dB per hundred feet at 30 MHz. Assuming about 200 feet of
cable are used to reach from the first floor to the roof of the above
example, plus some to reach the antenna set in from the edge of the
building and to reach to the transmitter, total loss is 2 dB. This

converts to a 37% power loss. However, the advantage of height
overcomes this loss in net coverage. Using the lighter cable,
RG-58/U, the loss due to the use of a long cable becomes significant.
RG-58/U cable has a rated loss of 3 dB per hundred feet. At 200 feet
this converts to about a 75% loss. In other words, only about 25% of
the power fed to the cable by the transmitter ever reaches the
antenna. Obviously, in this example, investment in the heavier cable
is worthwhile.

As a general rule, the heavier coaxial cable is nearly always used
for base station installations. The lighter cable is used for mobile
installations.

HOME ROOF MOUNTING

CB base station antennas mount to the same type of mast as TV
antennas. The U-bolt mounting clamps are the same. Any of the
methods of mounting described in Chapter 7 for TV antenna
mounting also apply to CB antennas.

Legal height limits may restrict the choice of antenna. Consider the
20-foot limit. A full /4-wave antenna height of 9 feet would limit you
to the use of only 11 feet of mast. A full ⁄2-wave antenna height of 18
feet would only allow you 2 feet of mast. A full %-wave antenna
height of 22.6 feet could not be used. Typically what is used in this
case is a 5-foot mast and a shortened !4- or %-wave antenna, or a
10-foot mast and a full-sized 4-wave antenna.

CONNECTING THE FEEDLINE

The best way to buy coaxial cable is in precut lengths with connec-
tors already installed. These are packaged in 2-, 5-, 20-, 50-, and
100-foot lengths. This cable includes two PL-259 type plugs already
installed on the ends.

Connect the cable plug to the antenna as shown in the closeup view
of Figure 12-3. Bring it straight down and tie it to the mast every 2 or
3 feet apart with wire ties. Run it into the house about the same as
you would TV cable, except that the standoff insulators made for TV
cables are too small to take RG-8/U. It does not matter if the cable is
near metal, because it has a shield under the outer cover. Any method
of securing it to the house or building will do as long as the cable is
not punctured in the process.

One of the best methods of bringing this cable into the house is
through a hole in the wall opposite the operating position. А
plumbing elbow whose inside diameter is at least twice the outside
diameter of the cable should be installed with the outside opening

Figure 12-3. Plug on end of cable 19.
screws into connector on all base т =
station antennas.

facing downward (Figure 12-4). This makes a waterproo
Caulk the outside openings, and plaster the inside Sud dorum
maintain the insulation of the building.

If the 50-foot cable is a bit longer than needed, ju: i
remainder under the operating table. There is not в ma
use of a small extra amount to warrant cutting it to exact length and
installing a plug. There is only a 12% loss in the entire length of 50 feet
of RG-8/U cable, so a few extra feet over will represent only a small
percentage of the 12%.

The other end of the cable with its plug installed is merely screwed
onto the output terminal of the transceiver or whatever CB
equipment is used. Later you will be shown how to connect PL-259
plugs to cables cut to length.

PLASTER
COAXIAL WALL

CABLE

Figure 12-4. The best way to bring
the antenna cable into the house.

GROUNDING FOR PROTECTION

Unlike a TV antenna, a CB antenna has a vertical element that
reaches up fairly high into the sky. This vertical element may be
insulated from the mounting plate and the mast. It connects to the
center conductor of the cable feeding the antenna. Protective ground-
ing is considered in detail in Chapter 15; it should be read thoroughly.

INSTALLING COAXIAL CABLE CONNECTORS

When bulk coaxial cable is used, the ends must be dressed, and
PL-259 plugs installed onto the ends. This takes some dexterity and
some experience in soldering, although there are some solderless
types of plugs, but these require special crimping tools.

Figure 12-5 shows how the ends ofthe cable are dressed. The inner
conductor is soldered to the center pin of the plug. Since the pin
protrudes out slightly in front of the shell, the inner conductor of the
cable is made slightly longer than the rest of the cable parts. The
braided outer conductor is soldered to the shell of the plug. The
length of each cut on the cable is easily determined by laying it
against the plug.

INSULATION

OUTER INSULATING
JACK
INNER CONDUCTOR

BRAIDED SHIELD

Figure 12-5. Preparing coaxial cable for soldering to a plug.

Unscrew the outer shell from the plug, and slide the shell onto the
cable, well below the end. Screw the plug onto the cable and solder the
center conductor to the pin of the plug. Solder the braided shield to
the neck of the plug through two of the holes in the neck. This is more
easily done by pretinning the shielded braid before inserting the cable.
It will take a hot soldering iron to solder through the holes of the plug.
This is shown in Figure 12-6A. Sketch B of this figure shows the com-
pleted assembly, after the outer screw-on shell is slid up and screwed
back into place. Note: Don't forget to slide the shell onto the coax
before soldering the plug.

100

SOLDER

(B) Assembled.

Figure 12-6. Coaxial cable connector.

101

СНАРТЕВ 13

INSTALLING THE MOBILE
ANTENNA

There is a wide selection of mobile antennas for CB use. The basic
kinds were described in Chapter 11. Each one comes with complete
instructions on how to mount them on a car. Considering that one is
working at ground level, it is not difficult to install a mobile CB
antenna.

Unlike the earlier days of CB, it is no longer necessary to drill holes
in the body ofthe car to mount a CB antenna. It may be preferable to
drill a hole to mount a "disguise" type antenna mentioned earlier, but
most antenna installations are done without driling holes. The
magnetically-mounted car-top antenna is probably the most conve-
nient.

TRUNK LID MOUNT

Two no-hole methods are used, the magnetic mount, and the edge
clamp. The magnetic mount is illustrated in Figure 11-17. The base of
the antenna is a powerful ceramic magnet which adheres to the metal
body of the trunk. This antenna could also be used to mount on the
roof as easily, except for the feed of the cable. The magnetic-mount
antenna is merely placed in position on the trunk lid, near the upper
edge. The feed cable is routed over the trunk lid edge and down into
the trunk. For secutity the antenna is easily removed and dropped in-
to the trunk through the opening at the back when the lid is up. Thus,
when your car is parked with no one in it, no antenna is visible.

The clamp-mount antenna has a U-like clamp at the back edge
which fits over the edge of the trunk lid. It is clamped in place with
screws that are underneath. It is fed by coaxial cable in the same way
as the magnetic mount. While the entire mount may be unscrewed

and the antenna placed in the trunk when you are not using the car, it
is more convenient to merely remove the vertical antenna element
from the mount and place it in the trunk, leaving the mount in place on
the trunk lid. By leaving the mount in place you may be advertising
the fact there may be a transceiver in the car, but at least the antenna
won't be stolen.

GUTTER-MOUNT ANTENNA

The antenna merely clamps to the rolled-up edge of the rain gutter.
The accompanying illustrations cover the installation of the Radio
Shack gutter-mount antenna. It is only 18 inches high, but has a
loading coil that makes it an electrical % wave long. It has attached
to it a length of RG-58/U cable which has a PL-259 plug attached on
the end. It comes ready to be immediately plugged into the CB
transceiver in the car.

Because of its small size and ease of installation and removal, the
gutter-mount antenna is intended for temporary use. Although its
short length reduces the risk of hitting low overpasses and other solid
obstructions, a spring at the bottom will give when obstructions,
such as low overhanging tree branches, are hit, with no damage to
the antenna.

Even though this resonates in the CB band, an antenna as short as
this must not be expected to give the results of one whose physical
length is the full М wave for resonating. For a temporary antenna,
however, results are good.

Figure 13-1 shows the details ofthe gutter-mount antenna. Figure
13-2 is a closeup of the clamp which holds to the inside of the gutter.
For mounting, the clamp is first loosened, then fitted over the gutter
and tightened. When held firmly, there is a tendency for the antenna
to bend towards the car body. An adjusting screw centered between
the clamping screws is turned in until its rubber tip presses against
the ear body to push the antenna into an upright position.

Figure 18-3 shows the antenna being mounted to the gutter of a
car. The cable is fed in through the window, and the plug screwed into
the antenna socket of the CB transceiver.

BUMPER-MOUNT ANTENNA

Because the bumper of a car is at a low level, an antenna mounted
to it can be a full physical 4-wavelength without the use of loading
eoils. While excellent results are obtained, there is some directional
effect due to the mass of the car body. The ideal installation,
electrically, would be on the top of the car body, in the center of the

103

INSULATOR 24

104

WHIP AND COIL
ASSEMBLY

Figure 13-1. Construction details of
the gutter-mount antenna.

CLAMPING
RUBBER TIP SCREW

Figure 13-2. Details of the gutter clamp.

Figure 13-3. Antenna being fas-
tened to a gutter rail.

roof. But an antenna physically a quarter-wave in length would
extend nine feet above the roof, which makes it rather impractical.

CONNECTING THE CABLE

The feed cable can be run to the transceiver in either of two
methods. One is to run it under the car chassis, into the motor
compartment, and back through the firewall to the transceiver. Wire
ties should be used to fasten the cable to nonmoving parts of the
chassis underneath. The other method is to go into the trunk, through
the wall between the trunk and the back seat, and under the edge of
the carpet to the transceiver. This is the method used most, and is
rather easy to do. The cable is less than М-їпсһ thick and easily fits
along the edge under the carpeting.

TUNING THE ANTENNA

The most effective radiation and reception with a transceiver is
when the antenna is resonant and the impedance matches that of the
coax. The 40 CB channels cover a total of .44 MHz in width, and com-
mercially purchased antennas will usually cover that width with good
efficiency.

Antenna length is related to its resonant frequency. For precise
resonance an antenna can be cut to an exact length. Some antennas
are made for easy adjustment. Others may need some trimming by
cutting off some length.

When the impedance of an antenna matches the impedance of the
connecting cable at a specific frequency it is said to be resonant to

that frequency and matched to that cable. So resonance is checked by
measuring the impedance match, and this is done with an instrument
called a SWR bridge. SWR means standing wave ratio. It is not
necessary to know the theory of standing wave ratio. Suffice it to say
the lower the ratio the closer the impedance match and the closer the
resonance.

The photo of Figure 13-4 shows a SWR tester. It requires no exter-
nal power to operate it. It works from the power output of the
transceiver. It is one of several standing-wave ratio (SWR)
instruments; the more expensive ones measure the SWR of high-
powered transmitters. Adjusting for minimum SWR, adjusts for
resonance and impedance match between transmitter and antenna. It
may be connected at the transceiver and left in the feed line per-
manently for observation of antenna performance.

Connect the SWR tester between the feed line and the transceiver.
Have the channel selector on a channel near the center of the CB
band. Turn the transceiver on and lock it in transmit position. Set the
switch of the SWR tester on "FWD" and adjust the right-hand knob
for full scale setting of the meter needle. Set the switch to "REF" and
read the meter. If it reads between 1:1 and 1:1.2 you are close enough
to resonance for excellent performance and no adjustment need be
made to the antenna. If the SWR reading is higher than 1.2 some
antenna length adjustment is necessary or the ground connection is
not good enough. Always check for poor ground connections before
changing the antenna.

The guttermount antenna described above adjusts typically.
Loosen the knurled lock nut at the bottom of the coil and slide the coil
up or down on the lower section of the vertical portion of the rod.
With each adjustment of length, make a new measurement of SWR.
Each time the SWR is measured reset to full scale in the FWD mode.

Figure 13-4. Micronta field strength-SWR tester.

106

The bumper-mounted antenna is a full 108 inches long with the
spring in place (the spring adds 6 inches to the length). At its full
length, it is nearly resonant to 26 MHz. To test this antenna, set up
the SWR bridge (SWR tester) as for the gutter-mounted antenna. The
SWR will probably be above 1:2. Using heavy-duty wire cutters, or a
hacksaw, cut one-half inch off the top and make a new measure-
ment. If stil not close enough, repeat the cutting operation
and remeasure. It may take as many as 10 of these cuts to reach
resonance, but it is advisable to take it a little at a time to prevent
going past the point of best SWR.

This same instrument has another feature. It is also a field
strength meter. By plugging about a 20-inch piece of stiff wire into
the *FS ANT" jack in the center, the instrument will pick up some of
the RF sent out by the antenna and the meter needle will move up.
Maximum output from the antenna usually means the antenna is
resonant and the ground plane (car body etc.) losses are low.

While the above applies as well to base station antennas, their
location is such that adjustments may be difficult to make. Ad-
justments are generally made only if the SWR over the entire CB
range exceeds the maximum specified for the transceiver.

USEFUL ACCESSORIES

A number of accessories are available to make installation more
flexible, or for transferring an antenna from one car to another, or to
a truck.

A hold-down clip (Figure 13-5) can be fastened to the gutter near
the front door of the car. When you need to lower a long antenna to
enter your garage, just bend it and clip it to this device.

Figure 13-6 is a no-hole trunk mount for use if you already have the
whip or vertical antenna.

Figure 13-5. A hold-down clip.

107

Figure 13-7 illustrates a bracket that mounts to truck mirrors and
accepts standard antennas with 38-24 thread up to 4 feet long. A later
model of this bracket also mounts to horizontal luggage-rack bars.

Figure 13-6. А no-hole truck mount.

Figure 13-7. A mounting bracket
that attaches to a truck mirror.

NOISE FILTERS

Because the frequencies of CB operation are high, noise
developed in the engine сап produce a hash-like sound in the CB
receiver. A number of filters are made to reduce or eliminate this
noise.

Figure 13-8 shows a heavy-duty inductance-capacitor filter to be
connected into the plus and negative leads to your transceiver. It
filters out noises coming through the supply line (12 V). Figure 13-9
shows an ignition noise suppressor. It plugs into the center of the
distributor, and the original wire into it. It is a resistor type. Figure
18-10 shows an alternate noise suppressor. It mounts on the alter-
nator to filter the 12 V output wire. Figure 13-11 shows a high-value
capacitor filter. Connect in-line at strategic places if other filters are
not effective enough. This may also be used in fixed-station applica-
tions when wired in series with the AC line to motors or other noise-
producing devices.

Figure 13-8. Inductance-capacitance

filter used in 12-volt supply line to DARCHER >
Cat. No, 270-060
пакене. HEAVY DUTY. NOISE FILTER
RATED 5 AMPS B-15VDC

109

Figure 13-9. Resistive-type ignition noise suppressor.

Figure 13-10. Alternator noise suppressor.

Figure 13-11.

High-capacity bypass capacitor for filtering high-frequency
noise.

CHAPTER 14

ANTENNAS FOR SHORTWAVE LISTENERS

Those of you who own a good shortwave receiver and like to listen
to foreign broadeasts as well as Voice of America, amateur radio
transmissions and other services on the shortwave band will increase
the fun of listening in with a good antenna. There is nothing
particularly special about a good antenna for this purpose. It needs to

be reasonably long, and up as high as possible.

THE INVERTED “L” UNIVERSAL ANTENNA

The most common type of antenna, and one which performs very
well, is the inverted “L,” which looks like just what the name implies,
an L upside down. Figure 14-1 shows the basic inverted L.

While the inverted L antenna consists of a stretch of wire which is
the antenna proper and a lead-in connecting the antenna to the
receiver, in performance the entire antenna and feeder are picking up
signals. There is a type of antenna in which the feed line does not pick
up signals, and this will be discussed a little later. The wire used need
not be an insulated, or covered, type. However, construction must be
such as to insulate the antenna from anything metallic or subject to
dampness through the use of insulators. The wire itself may be bare.
Stranded copper antenna wire is excellent for use and is easy to bend
and flexible in the wind. The antenna wire and the installation must
be sturdy enough to withstand high winds, the weight of sleet and
ice, and the extra pull when contracted by cold.

Every electrical circuit requires two wires, to carry the current to
the load and back again. The inverted L antenna requires a ground
for the return path. The ground post on the back of the receiver
should be connected to one of several grounds—to a cold water pipe
(never a gas pipe) in the house, to a metal radiator in the house, orto

112

NEAR SUPPORT
(HOUSE)

INSULATOR (2)

SOLDER LIGHTNING T] |^^ G

ARRESTER HI

GROUND MOVABLE
LINK

Figure 14-1. Basic inverted L antenna and details of installation.

a metal rod outside driven into the ground about 8 to 10 feet.

The ground post in the receiver is also connected internally, in the
receiver, to the AC lines through a capacitor. Very often the use ofan
external ground, one of the three mentioned above, gives no
improvement. The connection to the post in the ground has another
function—lightning protection—when a lightning protector is
connected to it.

PACKAGED COMPLETE ANTENNAS

You may purchase the antenna parts separately or buy a complete
package. An inexpensive one is shown in Figure 14-2. It consists of 75
feet of stranded antenna wire, 25 feet of lead-in wire, two
antenna-end insulators, two knob nail insulators for the lead in, and
aninsulated, flat copper lead-in strap for installing under the window
sash. For adding a ground and lightning protection, add a short piece
of heavy copper or aluminum wire, a grounding clamp, a ground rod
(Figure 14-3) and a lightning arrester.

THE HALF-WAVE FOLDED-DIPOLE ANTENNA

The antennas just described are called random-length antennas.
They are good for pickup of all frequencies in the shortwave range,
although they do peak at the odd multiples of a quarter-wave in
length. If your interest is only one shortwave band, an antenna cut to

Figure 14-2. А complete kit of parts for an inverted L antenna.

precise length, such as a half-wave twin-lead type folded-dipole will
give better results.

The sketch of Figure 14-4 shows an antenna made entirely of
300-ohm twin-lead cable. The top section is cut to resonate to the
desired frequency band. The formula for antenna resonance is:

468
(MH length (feet).
For example, to cover the foreign broadcast 19-meter band, first
convert meters to frequency by dividing into 300:

Figure 14-3. Ground rod and clamp for lightning protection.

399 = 15.79 MHz
By inserting the frequency into the resonance formula the length
comes out to be 29.64 feet. A length of 29 feet 8 inches is used.

The feeder and the antenna are made from the same kind of cable.
When you buy cable figure on the length of the antenna, plus the
length of the feeder to come straight down from the antenna for about
one-half the length of the antenna, then into the receiver.

Cut off a 29 foot 8 inch length of cable.Strip about one-half inch of
insulation from both ends of this piece. At each end solder the two
conductors together. At the very center cut one of the conductors.
Pull the two cut ends away from the rest for about one inch, and strip
the insulation from these ends back about one-half inch. From the
remaining length of the 300-ohm cable, strip the wires of insulation at
one end, and solder one wire to each wire exposed from the center of
the antenna section.

Only the 30 feet of antenna up in the air picks up radio waves. This
is good as the antenna should be above any noise developing sources.
The lead-in does not pick up radio waves. The two wires of the feed
line are out of phase with each other and cancel out any pickup of radio
noises. No ground is needed at the receiver, except for protective
purposes.

This method may be used to make antennas for any one of the high-
frequency shortwave or amateur bands.

SUPPORTING THE ANTENNA

Work for two objectives in putting up an antenna. Опе is to get it as
high as practical. The otheris to completely isolate it from any metals
or moisture-holding material. The highest point on the house is
usually one point of suspension. A high pole, neighbor's house, or tree
is the farther point of suspension. Insulation is by means of white,
glazed, porcelain-like insulators.

A blownup view of one point of suspension can be seen in Figure
14-1. Suspension at the other end is similar, except that no wire is
soldered to the end for a lead-in. A heavy-duty screw eye will hold
firmly in wood. In brick or stucco, an expansion anchor plug must be
installed before fastening the screw eye. It is easier, and just as good,
to find some wood member of brick or stucco homes, such as the facia
boards at the top. Be sure to screw into the supporting 2 х 4 rafter
holding the facia board, not into the facia wood only. Often the wood
used for facia board is redwood, which is not very strong.

A well-painted 2 x 4 or2 х 6sunk into the ground about four feet
is a good support for the far end. If this support is over 10 feet above

the ground, it may need to be guyed, to prevent the antenna wire
from pulling it out.

115

Figure 14-4. A 19-meter folded-dipole antenna.

Select an area clear of trees or other obstructions, to prevent the
antenna touching any tree limbs or other objects. If a tree is used for
the far end support, pick one with a sturdy trunk to prevent pull on
the antenna wire in a wind. If one ofthe higher limbs is used, a device
for allowing for wind sway must be included. This may be in the form
of a pulley, as shown in Figure 14-5, or spring loading. Be sure the
insulator is far enough out from the tree foliage to prevent
interference with the antenna proper. Use a safety line on the weight
to keep a falling weight from injuring someone.

INSULATOR
EY Z7 ANTENNA

SAFETY LINE

WEIGHT

Figure 14-5. Pulley and weight arrangement of an antenna system.

116

Do not use the utility pole as the far end support of the antenna. If
you do, then don't be surprised to find the utility company has cut
down your antenna some day.

In the case of a twin-lead antenna, both ends are considered far
ends, with the lead-in connected to the center. One end may be
fastened to your own house. However, the lead-in must be supported
во it comes away from the antenna proper at right angles to it for a
distance of about one-half the length of the antenna, if possible. It
must not parallel the antenna close by.

BRINGING IN THE LEAD-IN

It is just as important that the lead-in wire be insulated from other
metals or damp material as the antenna proper. The lead-in is part of
the antenna, in the case of the inverted L-type antenna. After
soldering the end to the antenna, bring the lead-in to the point of
entry, supported by nail-type insulators or TV-type standoff
insulators. This is especially important where the lead-in crosses
over a metal gutter. Place the insulators so the lead-in is carried
around and over the gutter, with a few inches distance between the
two.

Two methods are popularly used to bring the lead-in into the
house. One is through the window, and the other is through a wall.

The short strap pictured in Figure 14-2 is made of a flat piece of
copper, covered with flexible insulation and with a spring clip at each
end. It is well suited to the inverted L antenna and is the simplest
way to bring the lead-in into the house. It fits under the window sash.
With wooden sashes there is no metal proximity, except for weather
stripping. On metal sashes its proximity to the metal alters the
electrical length of the antenna to a small extent. In addition there
may be some signal loss on a rainy day.

Place the window strap in position on the window sill. Bend the
strap to fit the shape ofthe sill and any weather stripping. Slam the
window down on the strap, and the strap should form to the sill and
sash.

Cut the outside lead-in to a length to reach the outside clip on the
window strap. Skin insulation off the end ofthe wire and connect it to
the clip.

Going through a hole in the wall is better suited to a deluxe antenna
installation, such as the one just described with a matched impedance
feed line. The method is shown in Figure 14-6. A plastic pipe elbow is
used to prevent rain from coming into the hole. The plastic pipe is an
acceptable insulator so that proximity to the lead-in is not a factor as
it would be if metal pipe were used. Another method would be to use a
plastic wall tube shown in Figure 7-25. Be sure to weatherproof all
openings in the wall, inside and out.

117

LEAD-IN

Figure 14-6. А good way of bringing
the transmission line into the house.

PIPE ELBOW

WATER DRIP
LOOP

Make some measurements from each corner of the house to the
selected point of entry. Find a spot where there is no wall stud. Wall
studs are normally 16 inches apart, center-to-center in most homes.
Check the inside of the house at about that spot to make sure there is
no AC outlet below the selected area. If there is an AC outlet, avoid
the space between those studs as you may run into the conduit
carrying the wires or, worse yet, the wire itself in those cities which
permit plastic-covered cable without conduit for house wiring. Find
another pair of studs to go between.

On a brick or stucco house, a star drill or masonry drill bit will be
needed. Working from the outside, start in the mortared corner of the
brick and drill out a hole. Chip away at the brick until the hole is large
enough to take the lip of the pipe elbow. A wood drill is used for a
house with wood slats. A rough cut, round rasp file may be needed to
increase the size of the hole in wood.

The pipe elbow will hold to wood with epoxy cement. It will hold to
brick or stucco with epoxy, or a latex patching concrete mix.

CONNECTING TO THE RECEIVER

The back of a receiver will have two or three screw terminals for
connecting the antenna. Those with two terminals will usually be
marked A for antenna, and G or GND for ground. This type of
terminal is intended for the random-length, or inverted L-type
antenna. A wire connection is made between the window lead-in
strap clip, or other method of lead-in entry, to the A terminal.
Connect a wire between the ground terminal and a cold water pipe, a
metal radiator, or the wire coming in from the ground rod driven into
the ground on the outside. That wire may be brought into the house in

118

the same way as the lead-in. As mentioned once before, the receiver
may operate just as well without a ground connection, because an RF
ground is made inside the receiver to the AC lines, via the case itself.
Ifthe receiver is AC/DC powered, and has no ground terminal, never
go inside the case to make a ground connection.

A ground rod driven into dry earth, such as is found in the
Southwest, is not a good ground for signal pickup return. However, it
is a good ground for lightning protection, as discussed later.

Skin any insulation from the ends ofthe connecting wire and scrape
the copper clean with the blade of a knife or a piece of sandpaper.
Twist the end of the wire over the loosened terminal screw post in a
clockwise direction (Figure 14-7). This prevents the wire from being
squeezed out as the screw is tightened down.

Receivers with three-terminal inputs may be used for a single -wire
antenna, or a dual-wire twin lead. These terminals will usually be
marked A1, A2, and G or GND. If a single wire antenna is connected,
wire a jumper between A2 and G, as shown in Figure 14-8. Connect a
ground lead to G or A2. For a balanced wire lead-in, one wire is con-
nected to A1 and the other to A2. With a twin lead, or balanced line
lead-in, a ground is not necessary on the G or GND terminal (Figure
14-9).

The inverted-L antenna is also ideal to use when experimenting
with a crystal set or other simple receiver. Some of the best memories
I have are as a youngster competing with a neighbor on our home-

TO ANTENNA

P TO GROUND

Figure 14-7. Connecting a single-lead antenna to a receiver having a
two-terminal antenna block.

ТО АМТЕММА
TO GROUND

p Am
TWINLEAD

Figure 14-8. Connecting a single- Figure 14-9. Connecting a balanced
lead antenna to a three-terminal wire lead-in to a receiver.
antenna block.

built crystal sets. My friend was able to get better results until I
learned how to tune the antenna circuit. After this experience, I was
hooked on electronics and eventually became a ham and then an elec-

tronics engineer.

120

CHAPTER 15

SAFETY PAYS

If you value life and property forget about putting up an outdoor
antenna, whether it is a TV, CB, or shortwave antenna unless you
can observe certain precautions.

Nearby power lines on utility poles can be a hazard. A tower must
be located so that if it should fall from a high wind it will not fall across
electric wires. In addition atower must avoid the possibility of falling
onto someone else's property which could become damaged. Poles
and towers must be guyed keeping in mind the strongest possible
wind in your area.

А shortwave antenna is long. Don't ever be tempted to run it
across power lines, nor fasten one end to the nearby utility pole.
Running the wire across power lines is a sure invitation to possible
death. The danger is two-fold, getting the wire across the power
lines, and the possibility ofthe wire falling onto the power lines later.
Fastening one end to a utility pole includes the possibility of accident
while climbing the pole, and a good chance it will be cut loose later by
the power company. The poles are the property of the utility
company, and they have every right to cut your wire down.
Shortwave antennas should be installed at right angles to power lines
to reduce interference pickup from the lines.

IMPORTANT SAFETY RULES

When installing antennas for television, shortwave, CB or other
receivers the following safety rules should be adhered to strictly.
1. Perform as much antenna assembly as possible on the ground.

2. Observe if there are any overhead power lines nearby. The
installation should be a minimum of twice the maximum length

of antenna and mast assembly away from power lines. Thus, if

121

your antenna and mast length is 15 feet long, the closest power
line should be at least 30 feet away.

3. Remember that the mast, cable and metal guy wires are all
excellent conductors of electricity so keep them away from
power lines too.

4. Make sure your family and friends understand the danger of
the antenna touching overhead power lines. Tell them never to
try to remove any object that has come in contact with a power
line.

5. If any part of the antenna system should come in contact with
the power line, call your local power company to remove it. Do
not try to remove it yourself.

6. Ifafter all precautions an accident should occur with the power

lines

(a) Do not grab hold of a person who is in contact with the
antenna and power line.

(b) If you must remove the person in contact, use a dry board,
stick or a rope to push or pull the antenna away from the
victim.

. Do not use a metal ladder when installing the antenna.

. Do not install the antenna on a windy day.

. Donot mount the antenna on a tower or mast assembly over 30
feet long. Such an installation should be done by a professional
installer.

10. For masts, use only 14" antenna mast sections. Lengths over

10 feet should be guyed at least each 10 foot section.

11. If you are using plumbers-type waterpipe, use no more than a

10-foot length, because of excessive weight and guying

difficulties.

coo

CUTTING INTO A WALL

Running in-wall cable for connecting to wall-mounted outlets for
TV, or cutting through the outside wall for lead-in feedthrough
mentioned in previous chapters for TV and CB feeder cables poses
some problems. The danger is hitting AC lines in the wall.

Local codes vary throughout the country as to how the AC lines in
the walls are run. Some, like Chicago, require AC lines to be enclosed
in rigid metal conduit. Others, like Albuquerque, permit AC lines in
the walls to be a heavy-duty insulated cable but need to be in metal
conduit piping. When cutting into a wall where there exists the latter
type of AC wiring you run the risk of cutting into the AC lines.

Whether or not AC lines are in the wall at the spot you want to go

122

into it is determined by inspection. Observe if there is an AC outlet
just below the spot where you want to work. If your home is a
one-story home further inspection is by checking the points where
the AC cables may enter the wall. If your home has a crawl space
under it, the cables have probably been distributed to the various
outlets by means of the crawl space. If you have an attic, that was
probably the means of cable distribution. Inspecting these places will
tell you where cables are located.

ROOF SAFETY

Working at roof heights presents some hazards that must be taken
into consideration. This involves personal safety. If you have a heart
condition, and/or are up in years, and especially if you have not had
much experience at working on the roof, stay off. Let someone else do
it for you. There is a certain excitement in working on a roof, and
excitement that comes from doing something unfamiliar, and
observing extra caution against falling off, that makes the heart beat
faster, and calls for extra flow of adrenelin. Don't chance a stroke or
heart attack if you have any sort of heart disease.

Rubber soled shoes are a must if you work on the roof, especially if
it is a sloping roof. Avoid days of moderate to strong winds for
obvious reasons, and avoid a rainy day. Water can be a lubricant to
rubber soles, depending on the type of shingles. Be sure there is firm
footing at all times.

LIGHTNING PROTECTION

Protection from the effects of lightning takes on two forms. One is
to provide a continuous discharge of static electricity and therefore
prevent damaging potentials from causing hazard to life and equip-
ment. This is also thought to help prevent a direct strike of high-
energy lightning. The second is to provide a high-conductance path to
ground outside the buildings, or within the building structure in cases
of high-rise buildings, to ensure the passage of a direct lightning
strike without unnecessary damage to life and property. These two
forms are mostly provided by the same treatment, that is, proper
grounding of the antenna, mast, and tower system. The main dif-
ference in treatment is where the antenna cannot be grounded directly
without defeating its function. Only certain kinds of antennas can be
directly grounded.

Grounding is best accomplished as specified by the National Elec-
trical Code and other codes. First, a large-size conductor without
splices or other connections is connected between the base of the
antenna mast or tower directly to an earth ground. This conductor

123

should be of no smaller size than No. 18 AWG copper or No. 16 AWG
aluminum wire. Larger sizes are, of course, preferred. This ground
wire should be routed as directly to ground as practical. It should not
come near other conductors to which current must be prevented in
case of a lightning strike. It does not have to be insulated, but should
be kept clear of combustable materials. It must be protected from
accidental physical abuse, especially at and near ground level. This
might require the use of conduit (rigid or flexible) at or near ground
level.

The earth-ground connection is probably the weakest link in all
grounding systems. In order to obtain a high conductivity to earth,
there must be a large surface area in contact with conductive soil. In
areas of continuously wet or damp soil, this is easy to obtain, but in
dry rocky ground areas it is almost impossible. Some general rules
and ideas from past experience might be helpful here. First, wherever
possible, the ground system installed and used for the AC power lines
entering the building should be used. This also helps to keep potential
differences from this AC source from showing up between two
separate grounding systems. Usually though this only involves using
the same ground rod(s) which are used for the grounding of the elec-
trical system of the building. Connections to a ground rod should only
be by an approved clamp made for this purpose. An extreme example
of this shared system might be where a penthouse or high-rise ground
system may have to be a secure connection to the grounded conduit
system of the building.

Where you must install your own ground system, keep in mind that
ground rods driven into dry ground under overhanging eves are vir-
tually worthless. You must get at least 8 feet of ground rod into damp
soil to be effective. This might require using two or more rods driven
as deeply as the ground will allow and then bonding them together
with heavy wire and approved ground clamps. Dry soil can be soft-
ened by allowing a trickle of water from a hose to soak the area for a
day or more. You are allowed to use an angle of penetration up to 45°
from vertical in order to get a lot of rod under ground before being
bent or stopped by a layer of rock. In extreme cases, it may be best to
dig a trench 2.5 feet or more in depth and then lay 8 feet of ground rod
in the trench.

Some other effective ground systems include connections to cast-
iron well casings, buried masses of galvanized iron (old water tank,
pipe, etc.), and 8 square feet or more of buried copper sheet (flashing)
or other parts. Back when all water systems were made with
galvanized iron pipe, the outside faucet was popular; but now you
must also include at least one ground rod along with a water pipe con-
nection to ensure against a water system repair made with plastic

pipe.

GROUND WIRE LEAD-IN

Figuro 15-1. Installing a lightning
arrester and ground wiro.

INTO GROUND |

The discharge of static electricity from an antenna which can not be
grounded may take the form of an arrester. This is preferably
mounted either at the base of the mast or tower where the feed line
separates from it or just before entering the building. See Figure 15-1
for a typical arrangement. The arrester should provide both a high
resistance discharge path and closely-spaced arc gap to ground for
static charge. The device may be a simple resistor having a resistance
20 times the impedance of the cable or, as in the case of amateur and
CB equipment, an RFC (radio frequency choke) having an impedance
many times higher than the cable impedance of 50 ohms. Figure 15-2
shows an arrester for use on a TV 300-ohm twin lead. It has a strap
for mounting to a grounded mast or tower as well as a ground screw
for those uses at the point of entry to a building. Connections are
made to both lead-in wires by insulation-piercing washers. Figure 15-3

shows an arrester made for use by F-type connectors as used with
75-ohm coaxial cable.

Figure 15-2. Lightning arrester used with twin-lead cable.

125

Figure 15-3. Lightning arrester used with coaxial cable.

The best protection against damage from a direct lightning strike is
to remove the lead-in from the set and ground it to an outside ground
wire, and unplug the set from the AC outlet. Both of these actions are
required, as can be witnessed by many of us who have seen the effects
of direct hits on sets which were turned off, but you would never
know it by the extensive damage received as the lightning used the
TV set to find its way to the building's AC wiring and eventually to

ground.
SOIL EFFECTIVENESS

The effectiveness of any soil as a grounding medium depends on its
electrical resistance. While the resistance can be measured, this is
beyond the scope of this book. It is enough to say the lower the
resistance the better, and this is a function of the type of soil. Clay
type soil usually has a lot of moisture and is the best type of ground.
Sandy soil, such as in the Southwest is the poorest. A loamy or
organie (black) soil is somewhere in between.

The depth to which a ground rod is driven is important in this factor
of resistance. A rod driven only 2 feet into the soil has three to four
times the electrical resistance than one driven 10 feet down.

Grounding soil can be improved by treating the soil around the
ground rod, but is generally not recommended because of the cor-
rosive effects of the treatment chemicals and the need for periodic
maintenance which tends to be neglected.

126

INDEX

Amplified distribution systems, 41-43
Antenna

all-coverage, 14

CB/FM/AM disguise, 90-91

FM, 23-27

half-wave dipole, 23

height, need for, 30, 32

impedance matching, 82-83

Beam antenna, CB, 87-88
Broadband antennas, 8-9

с
CATV, 29
CB

antennas, 8
disguise (CBIAMIFM), 90-91
'4-wave, 84-85
half-wave coaxial, 85-86
ан унүн ground-plane, 83-85
indoor, 8
installation
fixed station, 96-101
mobile,102-111
mobile, 87-90
resonance, 81-83
frequencies, 81-83
ey mounting, TV antenna, 49-50
Coaxial antenna, alf-wave, CB, 85-86
Coaxial cable connectors, CB, 100-101
Color TV
antennas, 15
subcarrier, 12, 25
Couplers, impedance-matching, 38-41

Dipole, half-wave, a
Direct waves, 9
Disguise antennas (CB/AM/FM), 91-93

F
s-wave antenna, CB, 84-85
Fixed station antennas, CB
installation, 96-101

F
antennas, 23-27
frequencies, 13, 23
Frequencies, CB, 81-82
Fringe area antennas, TV/FM, 28-35

Ghosts, 9-11, 75
elimination of, 16-18

Grounding
for li hening protection, 123-126
soil effectiveness, 126

H
Height, antenna, need for, 30, 32
Herringbone pattern, 78-79

Impedance matching, 37-41
715-ohm coaxial са le, 40-41
300-ohm twin-lead, 37-39

Indoor antennas

FM, $970
TV. 6

АА саре" 43-46
Interference, TV, 75-80

127

L
Laws affecting CB antennas, 93-95
Lead-in, TV antenna, 54-58, 61-64
Lightning protection, 123-126
Long-range antennas, 30

Mast mounting, TV antenna, 53
Masts, antenna, 32-36
Mobile antennas, CB
installation, 102-112
accessories, 107-108
tuning, 105-107
Multipath signals, 9-10
Multiple-set distribution, 37-46

N
Noise filters, 109

o
Omnidirectional antenna, 23-25

P
Picture flutter, 80
Polar pattern, 17-18
Q
Quarter-wave ground-plane antenna,
CB, 83-84

R
Reflected waves, 9-10
Resonance, antenna, 8, 23
Roof mounting, TV antenna, 48-49
Roof safety, 123
Rotator, installation, 71-74
manual and automatic, 72-73

128

S
Safety rules, 121-122
Short-wave listener antennas, 112-120
half-wave twin-lead, 114-115
installation, 115-117
.64-wave antenna, CB, 84-85
Snow, 75
Sockets, wall mounting, 64-66
Sparking, 76-77
Standing-wave ratio (SWR), 106-107
Standoff insulators, TV antenna, 59-61
Stereo reception, 25-27
Subcarrier
color TV, 12, 25

T
Towers, antenna, 32-36
Translators, UHF, 14, 29
TV antennas
installation, 47-66
running the lead-in, 54-59, 61-64
Sockets, wall mounting, 64-66
mobile, 21-22
rotator, installation, 71-74
selection off, 16-22
UHF, 12-15
VHF, 12-15
TV interference, 75-80

ОНЕ antennas, 12-15
Unidirectional antenna, 23-24

v
VHF antennas, 12-15

w
Wall mounting, TV antenna, 50, 52-53

ӨМ

a
LI
B

yf hack

(о.
AON GOMEANY

ОЖ БУ, (СОВ BED

Related across Profoundd

Oregon Climate Docs

Ashland — Climate and Energy Action Plan (CEAP) p.19
Climate Impacts Every community will experience climate change differently. The geography, ecosystems, economy, demographic makeup, and social networks of a community all influence how climate change will affect a comm…
Ashland — Climate and Energy Action Plan (CEAP) p.357
1 Appendix C: Ashland Greenhouse Gas Emissions Projections and Target Setting Methodology Development of strategies and targets in the Ashland Climate and Energy Action Plan involved completion of the following …
Grants Pass — Sustainability and Energy Action Plan p.165
APPENDIX XII: MERLIN LANDFILL SOLAR CALCULATIONS GRANTS PASS SUSTAINABILITY AND ENERGY ACTION PLAN The cost to install 1 MW of solar power generation capacity in a ground mount solar power station ranges from $.89 to $1…

WEF Publications

Shoshana Zuboff — The Age of Surveillance Capitalism (Background) p.1
Welcome About The Age of Surveillance Capitalism Media TV & Video Podcast & Radio Reviews & Features Praise Awards and Honors Events Events Catalog Articles Buy US / Canada UK International Editions Other publishers/tran…
Arts and Culture Programme AM25 p.16
Kévin Germanier, a Swiss fashion designer celebrated for his sustainable approach, has transitioned from a Central Saint Martins student to a Louis Vuitton junior designer, and now to CEO of his own brand, Germanie…
Transformative Ocean Investment Opportunities 2025 p.22
22 Making Waves in the Regenerative & Sustainable Ocean Economy: Transformative Ocean Investment Opportunities 4. Ocean-based Renewable Energy Image: MoceanImage: Triton Anchor Image: Ørsted’s Borssele I & II Trit…

Epstein Files

EFTA01734882 — A6-DFR MAJOR AVIONICS SYSTEM LIST
ROYAL JET A6-DFR MAJOR AVIONICS SYSTEM LIST PRINCIPAL RADIO AND AVIONICS EQUIPMENT Equipment Quantity Manufacturer I Model/Part No. ATA Chapter 22 — Auto Flight STALL MANAGEMENT YAW DA 2 BAE SYSTEMS CONTROL 285A1010-6/-4…
EFTA01220987 — o Regulatory, Safety, and Environmental
o Regulatory, Safety, and Environmental Notices User Guide EFTA01220987 ob Copyright 2015-2017 HP Development Company. L.P. 8luetooth is a trademark owned by its proprietor and used by HP Inc. under license. ENERGY STAR …
EFTA00578359 — Wireless Network
Wireless Network Access Point ‘%. Use this guide to install: WAP11 ves 2.2 40=00 111 EFTA00578359 COPYRIGHT & TRADEMARKS Copyright 2002 Linksys, All Rights Reserved. Instant Wireless"" is a registered trade• mark of Link…

Federal Writers' Project

[Radio]
SWENSON 416v 19 193, On April 15, 1912, the unsinkable White Star Liner, S. S. Titanic, struck an iceberg and sank with a loss of 1500 lives off the icy grand banks. The radio operator, John George Phillips, sent the dis…
[Folkways, and Social Customs]
Accession no. W UNIT Form -3 0eAf-,7_4_ Collection (or Type) Date received /0/r.o/re. Consignment no. Shipped from Label Amount Title ..7‘;-erf-1-0,-07.-0.-• Place of origin Date./0,/-17 Project worker Project editor Rem…
[How Mr. Queen Became "King"]
Approxina SOUTH CAROLINA, WRITERS' PROJECT4 Life History elt TITLE: HOE MR. wpm BECAME *KING* OF THE BARBER MINES 10 (No fictitious names used 0. all true) Date of First Writing Nane of Person Interviewed Street Address'…