Telex FM Receiver 840-35A user manual

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RAYMER 


OPERATING INSTRUCTIONS 



WARNING: TO PREVENT FIRE OR SHOCK HAZARD. DO NOT EXPOSE THIS RECEIVER TO RAIN OR MOISTURE. 


DESCRIPTION 

The Raymer Model 840-35A is an all solid state 
monaural FM background music receiver with pro¬ 
visions for paging. The receiver consists of a tuner for 
the 88-108 MHz FM band and a 35 Watt RMS audio 
amplifier with a microphone preamplifier. 

The receiver has a music output and a preamp output 
jack for connection to an external amplifier as well as a 
high level phono input jack arxl a microphone jack 
which may be switched for either high or low im¬ 
pedance input. The speaker outputs of the receiver are 
for 4 or 8 ohms; or 25 volt or 70 volt balanced lines. 

The Model 840-35A also features an electronic music 
mute (precedence) circuit in place of a relay to quickly 
fade out the music while paging; after paging the music 
is smoothly restored. The receiver also has a variable 
tone control. 

UNPACKING 

The unit is to be removed carefully from the carton 
and inspected for any possible damage in transit. If 
there is any evidence of any damage which might have 
occurred in shipment, immediately notify your supplier, 
or the transportation company which delivered it. 
Claims for damage sustained in transit must be made 
upon the carrier. Save all packing material for in¬ 
spection by the claim agent who will furnish you with 
the proper forms and will also give you the necessary 
instructions for filing a claim. 

In addition to the unit the carton should contain a 
warranty registration card. To insure proper servicing 
and to protect your rights under the warranty, be sure 
to fill in the warranty registration card and mail to the 
factory within 10 days. 

INSTALLATION 

The Raymer Model 840-35A has ample vents for 
normal ventilation; however, it should be placed so as 
to permit free air flow around the unit. DO NOT PLACE 
ANY OBJECT ON TOP OF THE COVER OR IN ANY 
WAY BLOCK THE AIR FLOW OF THE VENTS. DO 
NOT STORE OR OPERATE THE RECEIVER in areas 
where the ambient temperature exceeds 140“F. 

The receiver may be mounted in a 5V4" vertical panel 


space in a rack, using a Raymer RPK-2 rack mounting 
kit. 

This unit has an AC line cord with a 3 prong plug. 
The line cord should be plugged into a 3 wire grounded 
105 to 120 volt 60Hz AC outlet. This will also ground 
the receiver. 

The AC receptacle on the rear panel is a 3 wire 
grounded outlet which can supply power to accessory 
or auxiliary equipment. Any auxiliary equipment con¬ 
nected to this AC receptacle is controlled by the 
POWER on-off switch so that turning off the power on 
the unit turns off all equipment. 

CONNECTIONS 

All connections are made on the rear panel of the 
unit. 

INPUT CONNECTIONS 

All patch cords and input leads other than Music 
Mute must be shielded cables. The Music Mute leads 
do not have to be shielded. When output leads are run 
near an unshielded microphone input plug, or when run 
together with the microphone precedence leads, a 
supersonic oscillation may occur. When this does 
occur, it will appear as a distortion in the amplifier 
output, and oftentimes will cause the circuit breaker to 
“trip." 

The Microphone input jack is for an unbalanced line 
only. If it is necessary to use a balanced input, an out¬ 
board matching transformer such as Raymer Model 
LMT-150 must be used. If the signal source is a tele¬ 
phone line or a 500 ohm input, the connection can be 
made to the amplifier by means of a Raymer Tele¬ 
phone Matching Adaptor TM-1 or TM-2. The switch 
above the microphone input selects the proper input 
impedance. The Hi-Z position will match either crystal 
or high impedance dynamic microphones; the Lo-Z 
position will match microphones in the 150 to 500 ohm 
range. 

CAUTION 

To avoid possible supersonic oscillation which 
might result in damage to the unit, it is mandatory 
that a shielded (metal cover) microphone plug be 
used. 


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If it is desirable to fade out the music while paging, a 
"dispatcher" type of microphone with an auxiliary 
switch having a pair of normally open contacts should 
be used. The microphone is to be connected as shown 
in Figure 1. 



FIGURE I. 

typical connection fora single microphone. 

FOR MORE THAN ONE MICROPHONE,CONNECT THE 
SWITCH CIRCUITS IN PARALLEL. 


The PHONO input jack enables the unit to amplify 
program material from a source other than the self- 
contained radio tuner. This input is high impedance 
with a maximum sensitivity of one-half volt and will 
accommodate the output of a ceramic phono cartridge 
or the output from any preamplifier such as tape, 
phono, etc. If the source into the PHONO input is from 
leased telephone lines, a Raymer TM-2 telephone 
adaptor is required to match the telephone lines to the 
input. 

PREAMP INPUT 

If it is desirable to add a signaling annunciator or 
alarm to the Music and Page system, a RAYMER 
MODEL TGSP-3 Tone Generator may be connected to 
the receiver. The output of the TGSP-3 should be con¬ 
nected to the PREAMP IN/OUT jack. By connecting ip 
this fashion the tone or alarm is unaffected by any of 
the front oanel controls. 

ANTENNA INPUT 

For normal FM reception, the short antenna lead 
supplied with the unit is sufficient for most locations. In 
the event that the tuner is located in a remote area, an 
external Dipole antenna will increase the number of 
distant stations that can be received. This external 
antenna is to be connected across the terminals marked 
FM ANT. 

OUTPUT CONNECTIONS 

The speaker(s) or line matching transformers are 
connected to the screw terminal board located on the 
rear panel. For short distances any ordinary insulated 
wire, such as parallel lamp cord, may be used. 


The 4 OHM or 8 OHM output is used when connec¬ 
ting directly to the speaker voice coils. When a speaker 
with an impedance of 8 ohms is connected to the 
amplifier, use the terminals on the amplifier marked 
GND and 8 . For a 4 ohm speaker or two 8 ohm 
speakers in parallel, use GND and 4 . 

The 25 VOLT or 70 VOLT output is used when con¬ 
necting to speakers which have line matching trans¬ 
formers. Connecting to the 25 volt or 70 volt tap on the 
unit permits the use of a number of speakers each 
with its own corresponding line matching transformer, 
thereby eliminating the necessity of calculating im¬ 
pedances. The tap on the line matching transformer is 
selected to give the power desired for each speaker. 
The total of all the power settings should be no greater 
than the amplifier output rating. If the speaker uses a 25 
or 70 volt line transformer, connect the speaker trans¬ 
former to the terminals marked COM and 25V (or 70V) 
according to the line desired. For an unbalanced line 
connect a jumper between COM and GND; if a bal¬ 
anced output line is used, no jumper is required. 

Long lines have an appreciable resistance with re¬ 
sultant power loss. The use of parallel matching trans¬ 
formers on either 25 volt or 70 volt lines is recom¬ 
mended for long distances. In all cases, it is advisable to 
run as heavy a wire as possible consistent with the 
requirements. To avoid inducing hum in the system, dp 
not parallel speaker cables with any AC line power 
cables. 

70 volt distribution systems often require the speaker 
lines to be run in conduit. To determine whether they 
should be run in conduit check with local city codes for 
70 volt system requirements. 

Optimum performance of any transistor amplifier de¬ 
pends on the proper current delivered at the output 
terminals. Connecting a total load impedance at any tap 
less than the impedance indicated on the back panel of 
the amplifier will cause the transistors to deliver more 
current than they were designed for and will deteriorate 
the performance of the unit and cause damage to the 
transistors. To prevent this from occurring and to 
protect the components, the unit is equipped with a 
circuit breaker that will trip if the output impedance is 
below the specified rated value; for example, if two 8 
ohm speakers are connected in parallel (resulting in a 4 
ohm impedance), and in turn connected to the 8 ohm 
output terminal, the circuit breaker will trip as soon as 
the volume control is turned up to the unit's maximum 
output. 

The circuit breaker located on the rear panel protects 
the unit from drawing excessive AC line current which 
could cause damage to the internal components. 

IN THE EVENT THAT THE CIRCUIT BREAKER 
CONTINUES TO TRIP, DO NOT ATTEMPT TO DE¬ 
FEAT THE FUNCTION OF THE CIRCUIT BREAKER. 
HAVE THE TROUBLE INVESTIGATED BY A QUALI¬ 
FIED SERVICE TECHNICIAN OR RETURN THE UNIT 
TO THE FACTORY. 


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MUSIC OUTPUT 

The Music Output jack may be used to connect to an 
external amplifier in order to operate a "MUSIC ONLY" 
system (such as MUSIC-ON-HOLD) simultaneously 
with the regular Music and Page function of the re¬ 
ceiver as shown in Figure 2. This output may be phono 
or tuner as selected by the music switch on the front 
panel and is not affect^ by the MUSIC MUTE. 

It may also be used to feed the signal from either 
phono or tuner to a tape recorder which has a Line in¬ 
put. 



MUSIC OUTPUT OF RECEIVER USED TO DRIVE EXTERNAL 
AMPLIFIER FOR SIMULTANEOUS MUSIC ONLY OPERATION. 


PREAMP OUTPUT 

The output from the PREAMP IN/OUT Jack may be 
connected to the input of an additional external ampli¬ 
fier if desired. The output from this jack includes both 
music and page so that both the receiver and the ex¬ 
ternal amplifier operate simultaneously. 


OPERATION 

The front panel has four knobs and three slide 
switches. The functions of the knobs are as indicated. 
The Microphone Volume Control knob adjusts the level 
of sound for paging or public address, and is indepen¬ 
dent of the Music Volume control knob. The Music 
Volume Control knob is used to adjust the level of the 
sound of the FM portion or phono. The Tone Control 
knob can be turned to the position that is most pleasing 
to the listener as it affects both the high and low fre¬ 
quency response. The Tuning knob is to select the 
desired FM station. The music switch is used to select 
radio, or phono. The slide switch at the lower left is to 
turn the unit on or off. The slide switch at the lower 
right is used for AFC defeat. 

AFC refers to Automatic Frequency Control and is an 
electronic means of keeping the receiver properly tuned 
to an FM broadcast station even when the tuning dial is 
not precisely set. However when tuning to a weak 
station which is adjacent to a stronger one the AFC 
function may tend to lock the receiver on the stronger 
station. In such a case the AFC switch should be placed 
in the OFF position. For very precise tuning or selection 
of a weak station the AFC switch should be placed in 
the OFF position while tuning. When the station is 
properly tuned the switch may then be returned to the 
AFC position to lock the receiver to the desired fre¬ 
quency. 

The LOG scale marking on the dial glass is for easy 
recording of the position of the pointer for any spe¬ 
cific station. 


WARRANTY 

This unit has been very carefully inspected and is warranted to be free from defects in material and workman¬ 
ship under normal use and service for a period of one year from date of sale to the original purchaser. This Warranty 
does not extend to any unit which has been subject to abuse, misuse, neglect, accident, improper installation, or 
alterations. The obligation of Trutone Electronics under this Warranty is limited to the repair of any defect in ma¬ 
terial or workmanship and/or the replacemnt of any defective part, provided the unit is returned to Trutone Elec¬ 
tronics Inc. transportation paid within the year. 

It is recommended that any unit on which service is required be processed through your distributor or installation 
company wherever possible. 

In order for the above Warranty to be in effect the Warranty Registration Card enclosed with the unit must be 
filled out completely and mailed within ten days of purchase. 

This Warranty is expressly in lieu of all other Warranties, expressed or implied, and of all other obligations or 
liabilities on our part. We neither assume nor authorize any other person to assume for us any other liability in con¬ 
nection with the products manufactured by Trutone Electronics, Inc. 


Made in U.S.A by 

TRUTONE ELECTRONICS, INC. 7315 Fulton Avenue • North Hollywood. California 91605 • (213) 875-0423 


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