ALAN Electronics Tectalk FM PMR 446 Service manual

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Document text

W PlbrechK 


The World in Communication 


Tectalk 


SERVICE MANUAL 

2-WAY PORTABLE 
HANDHELD 
PMR 446 RADIO 


Nov. 07. 2001 
ALAN Electronics GmbH 




CONTENT 


1. GENERAL 

1.1 General 

1.2 Characteristic 

1.3 Composition 

2. SPECIFICATION 

2.1 General Specification 

2.2 Electrical Specification 

3. OPERATION 

3.1 Key Name 

3.2 ICONS on LCD 

3.3 Key Functions 

3.4 Setting and Operation 

4. ADJUSTMENT 

4.1 Frequency synthesizer 

4.2 Transmitter 

4.3 Transmitter Test 

4.4 Receiver 

4.5 Receiver Test 

4.6 Symptoms, check point & Correction 

5. DESCRIPTION OF RADIO CIRCUIT 

5.1 Frequency Synthesizer 

5.2 Receiver 

5.3 Transmitter 

6. BLOCK DIAGRAM 

7. SCHEMATIC 

8. COMPONENT PARTLIST 

9. ASSEMBLY DRAWING AND PHOTOGRAPH 

10. CHANNEL DATA (With Sub-channel data) 



1. GENERAL 


1.1 GENERAL 

This equipment, Tectalk is called 2 way portable handheld radios. 

The frequency range is 446.00625 to 446.09375MHz, UHF operating channels for 
Europe-wide used 2 way portable radios according to PMR-446 Standard. 

1.2 CHARACTERISTIC 

a) All active device in this radio is composed of semiconductor and high 
density 1C. 

b) To design this radio in compact and weight approximately 140g including 
battery. 

C) CPU of this equipment is HD4048812B from HITACHI. 

d) It's power can operate by use of alcaline 4 cell (1.5V AAA) battery. 

1.3 COMPOSITION 

This radio is composed of following. 

a) Transmitter (W/Antenna) 

b) Belt clip 


2. SPECIFICATION 

2.1 GENERAL SPECIFICATIONS 

a) Frequency Range : 446.00625 to 446.09375 MHz 

b) Output Impedance : 50 Ohms Unbalanced 

c) Modulation Type : 8K50F3E 

d) Communication Mode : Simplex 

e) Channel Capacity : 8 channel 

f) Channel spacing : 12.5 KHz 

g) Power : 6.0V(ALCA 1,5V x 4AAA) 

h) Battery Life : ALCA.IOOOmAh > about 35hours 

NI-MH 600mAh > about 22hours 
( TX 5% ,RX 5% ,Standby 90% ) 

i) Operating Temperature : -20°C to +55°C 

j) Dimension : 95.5(H)x 50(W)x 26(D)mm 

k) Weight: 120g(with Battery) 

2.2 ELECTRICAL SPECIFICATION 
a) TRANSMITTER 

1) Output power: Max. 0.5W 

2) Frequency Stability : +/- 5PPM (-20°C to+55 °C) 

3) Modulation Method : FM 

4) Oscillation Method : PLL SYNTHESIZER 

5) Max. Frequency Modulation : < +/- 2.5 KHz (with tone) 



6) Cooling Method : air-cooling Method 

7) Spurious Emission TX : < -36dBm 

8) FM Hum/Noise : > 40dB(1kHz 60% modulation) 

9) Distortion : < 5% (1kHz 60% modulation) 

10) Tx Audio Response : 6dB /OCT +/- 3dB PRE-EMPHASIS(300Hz to 2.5kHz) 

b) RECEIVER 

1) Receive Method : Double Super Heterodyne 

2) Receive Sensitivity : -118dBm up (20dB SINAD W/CCITT) 

3) Squelch Sensitivity : -120 to -130dBm (Audio on/off point) 

4) Bandwidth : > 8.5KHz 

5) Adjacent channel rejection : > 55dB 

6) Local Frequency Stability : +/- 5PPM (-20°C to +55°C) 

7) Spurious Response Rejection : > 65dB 

8) Audio output: 200mW(8 Ohms load THD 10%) 

9) Distortion : < 5% (1 kHz 60% Modulation) 

10) RX Audio Response : 6dB/OCT +/- 10dB DE-EMPHASIS(300Hz to 2.5kHz) 

11) S/N Ratio : > 40dB(1kHz 60% modulation) 

12) IF: 1'st IF = 21.7MHz 

2'nd IF = 450kHz 

13) Local Frequency : 1 st Local Frequency = fc - 21,7MHz 

2nd Local Frequency = 21,25MHz 



3. OPERATION 


3.1 Drawing of the radio 




FUNCTIONS AND CONTROLS 

1) Battery Door 11) Down Button & Volume Control 

2) Monitor Button 12) Function Button 

3) Detachable Belt Clip 13) Power On/Off & Enter Button 

4) Push-To-Talk (PTT) Button 

5) Antenna 

6) External Mic / Speaker 

7) Built-in Speaker 

8) LCD Panel 

9) Built-in Microphone 

10) Up Button & Volume Control 





3.2 ICONS on LCD 


! Tull 

! 5. O O .. 

| X LJ U U. u u u. O j 



1) RSSI (Receiving Signal Strength Indicator) orTX Bar Icon 
Indicates the receiving signal strength during transmission and it can 
be indicated the number of bar according to the strength of receiving 
signal. It (TX Bar) is not transformed. 


T. 


2) Monitor Indicator 

Appears when the monitor button is used. 

3) CTCSS Indicator 

Blinks when the correct CTCSS tone is entered. 

4) Auto Channel Scan Indicator 

Appears in the auto scan mode or when the auto scan mode is 
activated. 

5) Dual Watch Scan Indicator 

Appears in dual watch scan mode or when the dual watch scan mode 
is activated. 

6) Key Lock Indicator 

Blinks in auto lock selection mode or when the key lock is 
activated. 


0 

o 

a 


7) VOX Indicator 

Blinks in VOX selection mode or appears when VOX is activated. 

8) Battery Level Indicator 

Battery Level Meter indicates the remaining battery strength. 

Blinking when the Battery charge strength is Low-cell only and then red 
LED Blinking at every 5sec. 

When the TOT Penalty is Warning Beeping at initial activation and not 
Transmit at lOsec. 


fti 


9) Tx Indicator 

Appears when a signal is being transmitted. 






10) Rx Indicator 

Appears when a signal is being received. 



11) Large Segment Display 

Indicates the channel number in use at the normal mode. 

When the Function Button is pressed, it Displays the function menu 
in sequence : 

CH / etc / SC / dW / VO / Vdt / ALo / CAL / tON / tAL / bEP 


o o o 

U U U. 


12) Small Segment Display 

Displays the CTCSS tone option at the normal mode. LJ 

CTCSS option is displayed in Hz. U 

Displays the SUBMENU of each MENU in the function mode. 

(e g. CH 1 to 8 / etc: 1 to 38, OFF / SC: up, dn, OFF / dW: 1 to 8, OFF / 
VO: High, Mid, Low, OFF / Vdt: 5sec, 3sec, 2sec, Isec / Alo: OFF, Auto / 
CAL number: 1 to 7, OFF / tON: no, Freq / tAL: On,OFF / bEP: On,OFF) 


0 0 
u u. 


O 

u 


3.3 Key Function 

3.3-1 ENTER BUTTON (#13) 

1) Short Touch - Power On 

- Press this button (#13) briefly to turn the unit on. 

A short confirming melody will play. 

2) Long Touch - Power Off 

Press this button (#13) for longer than 1.5 seconds to turn the 
unit off. 


Press it to confirm the required option for respective functions 
during function edit mode. 

3.3-2 FUNCTION BUTTON (#12) 

1) Short Touch 

- Press this button briefly to enter function edit mode in standby 
mode. 


2) Long Touch 

- Press for longer than 1.5 seconds to activate the KEY LOCK in the 
standby mode. 

Please note all buttons will be disabled except the Monitor 
Button (#2) and PTT Button (#4) will remain fully operational. 



3.3-3 UP BUTTON (#10) 


1) Short Touch 

- In the standby mode, press this button briefly to move to the next higher 
main volume level. 

In the function edit mode, press briefly to shift from the current option 
in each submenu to the next option in the same submenu. 


2) Long Touch 

- Pressing this button for more than 1.5 seconds will allow you to navigate 
at a more rapid rate through different volume level in the standby mode or 
through different menus in the function edit mode. 

mode. 

3.3- 4 DOWN BUTTON (#11) 

1) Short Touch 

- In the standby mode, press this button briefly to move to the previous 
lower main volume level. 

In the function edit mode, press briefly to shift from the current option 
in each submenu to the previous option in the same submenu. 

2) Long Touch 

- Pressing this button for more than 1.5 seconds will allow you to navigate 
at a more rapid rate through different volume level in the standby mode or 
through different menus in the function edit mode. 

3.3- 5 PUSH-TO-TALK (PTT) BUTTON (#4) 

- Press it firmly and speak into the Built-in Microphone (#9) to transmit. 

The red Tx LED Indicator at the right side of the LCD Panel (#8) will 
light. 

- Release it to revert to standby mode. When an incoming call is received, 
the green Rx LED Indicator on the left side of the LCD Panel(#8) will light. 

- 2-Way Call Ringer: 

Press the PTT Button twice quickly to call another party on the same 
channel. The word CALL and the Tx icon will appear in the display. 

The user selected call ringer melody will play. 



3.3- 6 MONITOR BUTTON (#2) 

- Press it to check activity on the current channel before you try to 
transmit. 

- Adjust the Volume Control (#10, #11) if necessary. 

- When you press the Monitor Button, the LCD Panel (#8) will be illuminated 
with an amber color back-light and both the Tx and Rx LED indicators will 
light. 

- It can be activated by pressing Monitor,up/down ,enter and function key. 

- If you press the Monitor Button during the function edit mode, you will 
return to standby mode directly. 

- To setup Auto Monitoring ,press Monitor key for three seconds. 

3.3- 7 EXTERNAL MIC/SPEAKER (#6) 

- This jack accepts an optional headset/microphone for totally handsfree 
operation. 

Please refer to the enclosed Accessory Order Form to order accessories. 
See also section regarding VOX SELECTION MODE. 

3.4 Setting and Operation 

3.4- 1 BASIC CHANNEL SELECTION 

In order to communicate with other sets,both you and the receiving party 
Must be on the same channel. 

The set has 8channels (1 -8) as indicated by the large digits in the LCD 
Display Panel (#8). Before, trying to transmit on the selected channel,you 
should press the Monitor Button (#2) to check the activity on that channel. 

If someone is already on the selected channel, you should try another channel 
that is clear. 

To change the basic channel, 

- In the standby mode, press the Up Button (#10) briefly to move to 
the next higher main channel number. 

- Press the Down Button (#11) briefly to move to the next lower 
main channel number. 

3.4- 2 CTCSS (Coded Tone Controlled Squelch System) SUB-CHANNEL 

SELECTION MODE 


This feature allows you to utilize a less used channel range (01-38) within 
a main channel. This enables you to communicate with another party on the 



same main channel using the same subcode.This helps to avoid congestion on 
the main channel and filters out unwanted noise and static. 

There are 38 CTCSS subchannels for each main channel. 

To change the CTCSS subchannel, 

- Press the Function Button (#12) until the word cTc appears in the LCD 
Panel (#8). 

- Press the Up Button (#10) or the Down Button (#11) to choose the desired 
subchannel to use. The corresponding subcode frequency will be displayed 
in the lower right corner. 

- Press the Enter Button (#13) to confirm your selection. 

NOTE: To communicate with other PMR units, they must be switched to the same 
channel and CTCSS subcode. 

To communicate with other PMR units that do not have subcodes, 
switch your unit to the same channel with the subcode set to OFF. 


3.4-3 AUTO CHANNEL SCAN MODE 

This feature allows you to scan for an active channel and communicate with 
the party transmitting. 

To access the Auto Channel Scan menu, 

- Press the Function Button (#12) until the auto channel icon blinks 
and SC appears in the LCD Panel (#8). 

- Press the Up Button (#10) or the Down Button (#11) to choose scanning up or 
down from the current channel number. 

- Press the Enter Button(#13) to confirm your selection. 

- The unit will begin scanning for an active main channel. It is able to 

transmit by scan start channel during scanning. 

- When the scan release , the unit will be standby in scan start channel during 

Scanning. 

- Press briefly the Monitor Button , It allows you to skip over current channel 
on the scan list. On the other hand press long the Monitor Button , It allows 
you to delete current channel on the scan list. 

- To turn off the auto channel scan feature in the standby mode, simply press 

the Function Button(#12) once. 


3.4-4 DUAL WATCH SCAN MODE 

This feature allows you to monitor two different channels at the same time. 

If you pre-set any priority channel other than the current channel in use, the pre-set 
channel will be scanned every 0.5 second and signals you when a call is received. 

To access the Dual Watch Scan menu, 

- Press the Function Button (#12) until the dual watch icon blinks and dW 



appears in the LCD Panel (#8). 

- Press the Up Button (#10) or the Down Button (#11) to select the desired 
channel number you wish to closely monitor. 

- Press the Enter Button (#13) to confirm your selection. 

- To turn off the dual watch feature in the standby mode, simply press the 

Function Button (#12) once. 

3.4-5 VOX SELECTION MODE 

The Voice Activated Transmission (VOX) function allows your voice to activate 
transmission automatically when the Communicator is used with the optional 
handsfree mic/headset (refer to enclosed Accessory Order Form). It also allows 
handsfree use when a mic/headset is not being used without having to use the PTT 
Button (#4). 

To access the VOX Selection menu, 

- Press the Function Button (#12) until the VOX icon blinks and VOX appears in the 

LCD Panel (#8). 

- Press the Up Button (#10) or the Down Button (#11) to select from high,mid, 
low or off. High, mid or low setting determines VOX response sensitivity. 

- Press the Enter Button (#13) to confirm your selection. 

- To turn off the VOX feature, enter the VOX selection mode and then select 

Off. 


3.4- 6 VOX RECOVERY TIME SELECTION MODE 

This allows the response characteristics of the VOX function to be precisely 

adjusted to suit individual needs. 

To access the VOX Recovery Time Selection menu, 

- Press the Function Button (#12) until Vdt appears in the LCD Panel (#8) with 
the VOX icon blinking. 

- Press the Up Button (#10) or the Down Button (#11) to select from 5,3,2,or 
1 second setting. This setting determines the delay time between transmitt 
-ing and receiving. 

- Press the Enter Button (#13) to confirm your selection. 

- Please note you may need to try different VOX time settings to determine 
the best value to suit your speaking habit. 

- To turn off the VOX feature, enter the VOX selection mode and then select 
Off. 

3.4- 7 AUTO KEY LOCK SELECTION MODE 

This feature prevents accidental channel change and disturbance to the preferred 

Settings of the Communicator. Auto Key Lock temporarily disables the UP,DOWN 

And Enter Buttons. 

To access the Auto Key Lock Selection menu, 

- Press the Function Button (#12) until the auto lock icon blinks and Alo 
appears in the LCD panel (#8). 



- Press the Up Button (#10) or Down Button (#11) to select the Auto option. 

- Press the ENTER key to confirm your selection. 

- If you do not press any key for more than 15 seconds in the standby mode, 
all respective keys will automatically be locked. 

- To turn the auto key lock on or off in standby mode, simply press and hold 
the Function Button (#12) for more than 1.5 seconds. 

- To quickly activate the Auto Key Lock, hold the Function Button (#12) for 
more than 1.5 seconds. 

3.4-8 CALL RINGER MELODY SELECTION MODE 

This feature provides 7 user selectable call ringer melodies to alert you of a 
calling party. 

To select your favorite Call Ringer melody, 

- Press the Function Button (#12) until the call icon blinks and CAL appears 
in the LCD panel (#8). 

- Press the Up Button (#10) or Down Button (#11) to preview the 7 available 
melodies. 

- Press the ENTER key to confirm your selection. 

- By using PTT key, the mode will be changed from calling to transmit mode, 
stopping current calling. 

- If you set this function to call off, call function is disabled in this 
Mode. 


3.4- 9 TONE DISPLAY SELECTION MODE 

This feature allows you to select the preferred display format for the CTCSS 
code setting. 

If frequency “FrEq” was chosen, then the display in the CTCSS will be shown 
as frequency. However, if the number “no.” was chosen,then the code number 
will be displayed in CTCSS function. 

- Press Function Button (#12) until “tON” appears in the large display. 

- Press Up(#10) or Down(#11) to change the format. 

- Press Enter(#13) to confirm your selection. 

Otherwise, the displayed state is automatically accepted if no 
key is pressed after 5 Seconds. 

3.4- 10 SQUELCH TAIL SELECTION MODE 

This feature allows you to set option mode of squelch tail 
elimination. 

- Press Function Button (#12) at the CTCSS display option mode,you can 
select On or Off with Up(#10) or Down(#11) button. 

- When you press Enter Button (#13) or not press any key in 5seconds, it 
returns back Stand-by mode with back beep sound after installation squelch 
tail elimination option its setting. 

- Transmit Roger tone 400ms after PTT release. 



3.4-11 BEEP TONE SELECTION MODE 


This feature allows you to program beeping or not beeping with key selection. 
To set key beep mode, press the function key at the squelch tail ON /OFF mode 
at the same time operate beeping according to the tone of key beep. 

- You can select On or Off with Up or Down key. 

- When you press Enter button (#13) or no press any key in 5seconds. 
it returns back Stand-by mode with back beep sound after 
installation key beep option its setting. 

- To turn on the button beeps features, select Beep On. 

- To turn off the button beeps features, if you want quiet radio 
operation select Beep Off. 


4. ADJUSTMENT 

4.1 Frequency synthesizer (PLL) 

a) After connecting the power meter and dummy load ( to internal 50 Ohms connection 
point), join the antenna connection cable with above equipment. 

b) Check the voltage between TP & GND in digital voltmeter. 

c) Then set the low channel of set the lowest frequency. 

c) After pressed PTT key of set, trim VC1 for adjusting the lowest frequency 
Frequency of TX channel to DC 1.5V in the voltage of TP1. 

d) After releasing the PTT key, And then check if the highest frequency of 
Rx channel is within DC 0.6 ~ 2.3V in the voltage of TP. 

4.2 TRANSMITTER 

a) Connect EUT & measure equipment according to block diagram below. 
















b) Connect DC 6.0V, voltage preset to EUT. 

c) Connect "power meter" & "dummy load (50 Ohms)". 

d) Adjust Tx frequency according to trimming trimmer VC2. 

e) Connect AF oscillator to mic terminal for conform modulation degree. 

f) Adjust the frequency of AF oscillator to 1 kFIz and adjust AF level 

should be 60mV. 

g) Checking oscilloscope and modulation meter, max. 
frequency deviation should be in +/ -2.5 KHz. 

4.3 TRANSMITTER TEST 

a) Output Power Test 

Power(6.0V DC) should be Max.500mW. 

b) Audio Response 

Connect AF oscillator to Mic terminal and then firm the audio level 
that doesn't distortion the wave of oscilloscope in the frequency 
range, 300Hz to 3kHz. Check the audio level for 300Hz to 3kHz based on 
frequency standard, 1kHz. 

c) Modulation Degree Test 

1) Connect AF oscillator to the MIC terminal and then adjust the level to 
To 60mV 

2) Measure the oscilloscope wave and he point needle of modulation meter 
After pressing PTT key. 

3) Sweep gradually the frequency of AF oscilloscope from 300Hz to 3KHz. 
3kHz. 

4) At this time, the point needle of modulation meter should be in 
+/- 2.5 KHz. 

d) Spectrum Test 

1) Antenna is 50 Ohms and attenuator degree should be 20dB more. 

2) observe the spectrum with pressing PTT key. 

The harmonics should be less -36dBm than carrier. 

4.4 RECEIVER 

a) Preparation 

1) Adjust the power supply to DC 6.0V 

2) Adjust Voltage level to 0.7Vrms (8 Ohms load) after power on. 

b) Connection method 




















C) Conform of Rx sensitivity 

1) Adjust SSG to channel frequency. 

2) Adjust modulation frequency, 1kHz to modulation degree, 1.5KHz. 

4) After adjusting the frequency of SSG to channel frequency, RF level sets 
to -47dBm. 

d) Conform of Squelch sensitivity 

1) Set the standard channel. 

2) In squelch mode, SQ volume RV1 must be turned counterclockwise. 

3) After adjusting SSG to channel frequency, the adjusting SSG to level. 
-120dBm set is audio on, -130dBm set is audio off. 


4.5 RECEIVER TEST 

a) Rx sensitivity test(field strength) 

SSG should be adjusted to 20dB of SINAD's point need seeing wave of 
oscilloscope as SSG sets in 1 kHz with 1,5KHz frequency deviation. 

At this time, normal RF level is < -118dBm. 

b) Audio Distortion Test 

1) SSG should be adjusted like way of point a) and RF level sets to -47dBm. 

2) Adjust to 0.7Vrms(8 Ohms load) seeing Audio wave. 


3) Read the needle of distortion meter(normal condition would be less than 
5% distortion.) 

c) Squelch Test 

After RF level of SSG should be set to the least level, RF level should be 
gradually increased until speaker makes audio sound. 

At this point, check RF level(Check Audio on : -120dBm, Audio off: -130dBm) 


4.6 Symptoms, Check point & Correction 

a) Diagnosis method 

1) Check each switch to work well. 

2) Check voltage of battery. 

3) Problem develops from transmitter or receiver? 

b) Troubleshooting 
1) Transmitter 

-Power key is on condition but does not work. 
Battery could completely discharge. 

Battery cell twist.. 

Touch problem come between Battery and Radio. 



- Fail to transmit 

Run out of battery or charge problem. 

Fault of PTT key. 

Fault of Q4, Q5. 

- Transmitter works but frequency is unmatched 

Out of order in frequency synthesizer. 

Out of order in X-tal(X2). 

- Audio does not sound(Tx power and Tx frequency are normal) 

Problem of microphone or Mic connector. 

1C U7 problem. 

- Tx is set when switch is on. 

Tx switch problem 


2) RECEIVER 

- Rx does not work 

Speaker line open problem or connector problem. 
Receiver power circuit problem. 

Audio amplifier Base band 1C U4 problem. 

- Only noise sound 

U12 problem. 

VCO problem. 

- Rx sensitivity is weak 
Antenna mounting problem. 

Front-End circuit problem. 

Local oscillation frequency deviation. 

SF1 saw filter fail. 

VCO problem. 

- Squelch does not work 

U12 problem. 

Control logic problem. 


5. DESCRIPTION OF RADIO CIRCUIT 
5.1 Frequency synthesizer 

Frequency synthesizer consists of VCO, PLL IC(built in PRESCALER) and loop 
filter. 

a) VCO 

VCO is composed of ONE VCO. Oscillation circuit takes colpitts circuit using 
variable Diode. And VCO is composed of D1, Q8, Q9,C81 ,C75,VC1 ,L1 ,C74,C76. 
VCO control voltage through loop filter adjusts frequency and Microphone 
signal through Modulation terminal makes modulation. 



b) PLL 1C 

PLL 1C is adjustable 1C to produce the wished frequency which VCO provides 
through loop filter. 

It has internal counter using 21,25MHz reference frequency to make 6.25KHz 
as reference Signal. 

VCO frequency from prescaled input is divided signal is compared with Refer¬ 
ence signal phase in phase comparator. 

Built-in charger pump changes voltage (until two signals are in phase) and 
charged voltage supplies VCO through loop filter to produce the desired 
frequency. 

Frequency data associated with channel goes to PLL 1C by CPU through CLOCK, 
DATA. PLL 1C enables by strobe line of CPU. 

c) Loop Filter 

Loop filter is composed of R48,R49,C84,C85 and changes pulse from pinl 4 to 
DC. and eliminates harmonic component in pulse. 

It helps VCO oscillate clearly as DC voltage is supplied into varicap. 


5.2 RECEIVER 

This is composed of Dual Conversion Super Heterodyne. First IF is 21,7MHz. 
Local oscillator frequency is lower in 1 'st IF than Rx frequency. It is 
called low side injection. Second IF is 450kHz. 2 nd local oscillator frequ¬ 
ency comes to 21,25MHz. 

a) Rx/Tx Conversion Circuit 

Rx signal goes to Rx/Tx conversion circuit through FIXED antenna connector, 
low pass fiiter(L5,L6,L7,L18,C42,C43,C45,C46,C47) and receiver resonance 
circuit composed of L8,C1. When transmitting,voltage through R25,L12,D6 
supplies,D7 of receive input is short and Tx is on condition. When PIN diode 
off in condition of Rx,L8 and Cl resonate serially and make impedance match¬ 
ing at receiver bandpass filter. (SF1). 

b) Front End 

Front-End has Q1 to provide a high sensitivity and low noise feature. 

It employs Saw filter as band pass filter to eliminate image frequency and 
to produce enough pass band by Q1 input and output. 

c) Mixer 

Mixer has one base BFQ 67W(Q2) to feature high low noise quality. 

It has RF signal through L7, L8, SF1 ,SF2 and Q1 RF signal from Local oscill¬ 
ator mixed. 

It develops 1'st IF ,21.7MHz. 1st IF goes to 1st IF amplifier Q3(KTC4080) 
base through X-tal filter XFI. 

IF of mixing signals is selected and taken into X-tal filter. 

Output impedance of mixer is direct matched with input impedance of X-tal 
filter. 



Matching of filter satisfies pass bandwidth of filter, ripple elimination 
with in pass band, and attenuation characteristic of stop band. 

X-tal filter is composed of two pole monolithic X-tal filter, 

8kHz of IF bandwidth R11 is used as impedance matching with 1'st IF Amp Q3. 

d) IF AMP and Detection 

1 'st IF AMP Q3 supplies IF(U12) mixer input pinl 6 through output resistor 
R13 and C21 to need gain in insertion loss of X-tal filter and last stage 
circuit. Multi-use IF 1C makes up of mixer IF AMP. Pinl 2 nd local frequency 
frequency enter to pin 1. 

It supplies mixer of internal 1C. Mixer output of 1C through pin3 passes 
450kHz ceramic filter, supplies 2 nd IF amplifier and limits. 

After 2 nd IF AMP has a process of enough gain and AM rejection,it comes to 
quadrature detection. Demodulated audio signal by T1 (Quad Coil) is amplified 
and comes out to pin9. 

Detected audio signal through R22, VR1 and input in audio amp.1C U4 through 
C22. 

e) Squelch Circuit 

Noise component of detected outputs has amplification squelch threshold is 
controlled by Resistor R18,C31 ,R15. 

f) Audio Amplifier 

Demodulated audio signal enters to pin2 of U4. After above signal amplies in 
U4 pin5 through C220. It comes out to pin5 Then, It reaches at speaker. 

5.3 Transmitter 

When Tx develops with pressing PTT switch, VCO output amplifies through Q4, 
Q5 transmits by antenna through low pass filter. 

Tx RF signal produced from Tx VCO is amplified by DRIVER Q5 through C53 and 
entered Q4 POWER TR input terminal with final amplification. 

After this stage, the signal is emitted at antenna through 50 Ohms matching 
circuit to low pass filter (L5,L6,L7,L18,C42,C43,C44,C45,C46,C47) to elimin¬ 
ate harmonic. 


5.3-1 Audio Modulation and Audio Amplification 

Audio signal produced by external or internal microphone,limits amplification 
by 1C U7.. It enters to VCO through low pass filter and U2. 

Max. Frequency modulation deviation is adjusted by VR1 keeps noise and audio 
from entering to VCO at time of TX. 

Audio modulation and Audio Amplification has characteristic of 6dB/OCT pre¬ 
emphasis by U7(NJM324V). 



BLOCK DIAGRAM 



CONTROL BOARD ' RF BOARD 















































































































































/VALUE MA 





8. COMPONENT PARTLIST 


Tectalk 

Tectalk.SCH 

Bill Of Materials November 

Item Quantity Reference 


Revised: November 7,2001 
Revision: ??? 

8,2001 9:18:20 Page 1 

Part 


1 1 ANT ANT 

2 1 C9 5P 

3 7 C1,C12,C30,C42,C43,C63, 4P 

C81 

4 21 Cl 3, Cl 4,Cl 7,Cl 9,C20,C21, 102 

C23,C31,C52,C55,C64,C82, 
C83,C92,C112,C113,C127, 

C141 ,C147,C149,C154 

5 13 C2,C41 ,C67,C78,C79,C89, 220P 

C91 ,C93,C94,C95,C109, 

C155,C163 

6 4 C15,C44,C45,C46 6P 

7 5 Cl 6,C36,C47,C48,C75 10P 

8 27 Cl 8,C26,C28,C33,C34,C51, 104 

C56,C57,C65,C115,Cl 18, 

C121 ,C123,C125,C129,C134, 

Cl 40,Cl 45,Cl 46,Cl 48,Cl 59, 
C164,C169,C171 ,C172,C173, 

Cl 75 

9 7 C22,C35,C61 ,C66,C88,C122, 1u 

Cl 42 


10 

10 

C24,C32,C111 ,C114,C130, 

Cl 31 ,C143,C153,C161 ,C162 

103 

11 

1 

C27 

474 

12 

1 

C29 

100P 

13 

1 

C37 

39P 

14 

1 

C38 

56PU 

15 

1 

C39 

33P 

16 

1 

C49 

2P 

17 

2 

C53,C59 

15P 

18 

1 

C54 

12P 

19 

4 

C62,C68,C71 ,C74 

IP 

20 

2 

C69,C72 

8PU 

21 

1 

C73 

3P 



22 


1 C76 


2P2 


23 

2 

C84,C156 

224 

24 

1 

C85 

3.3/6T3 

25 

2 

C86,C157 

223 

26 

3 

C101 ,C103,C107 

22/4T 

27 

2 

OP1,C 

OPEN 

28 

1 

C105 

100/6E3 

29 

1 

Cl 06 

47/16E 

30 

3 

C124,C126,C128 

22P 

31 

2 

C132,C177 

393 

32 

1 

Cl 33 

820P 

33 

1 

Cl 52 

473 

34 

1 

Cl 74 

472 

35 

1 

C220 

220/6E3 

36 

1 

CF1 

CF450UG 

37 

2 

JJ7,CHARGER- 

- 

38 

4 

D3,D6,D7,D10 

KDS114 

39 

2 

D5,D8 

KDS160 

40 

1 

D22 

SM-2333T,GRN 

41 

1 

D 

off 

42 

1 

D1 

MA2S372 

43 

1 

D9 

KDS226 

44 

1 

Dll 

KDS120 

45 

1 

D21 

SR-2333H,RED 

46 

2 

D25,D26 

KDS184 

47 

1 

E7 

XX3P 

48 

1 

HI 

30mmX2 WIRE 

49 

1 

J1 

STERO 

50 

1 

J4 

2 2X1 

51 

1 

LI 

10n,(E2-320904T-R) 

52 

3 

L2,L11,L17 

470n,(FI-B1608) 

53 

1 

L3 

47n,(CI-B1608) 



54 

2 

L4,L12 

270n,(FI-B1608) 

55 

4 

L5,L7,L8,L15 

24n,(E2-281106T-R) 

56 

2 

L6,L18 

28n,(E2-281106T-R) 

57 

1 

L9 

22n,(CI-B1608) 

58 

1 

L10 

39n,(CI-B1608) 

59 

1 

LI 3 

31 n,(E2-281106T-R) 

60 

1 

LI 6 

8n2,(CI-B1608) 

61 

1 

LCD1 

TTR3264DPFDHN 

62 

1 

MIC1 

CMP4540 

63 

1 

Q3 

KTC4080 

64 

1 

Q4 

AT-31625 

65 

1 

Q5 

BFP193 

66 

5 

Q1 ,Q2,Q7,Q8,Q10 

BFQ67W 

67 

8 

Q19,Q23,Q27,Q28,Q29,Q31, KRC404 

Q32,Q33 

68 

1 

Q9 

2SC4226 

69 

3 

Q21 ,Q24,Q26 

KRA306 

70 

1 

Q22 

KTA2015 

71 

1 

Q25 

KRA305 

72 

2 

Q30,Q35 

KRA304 

73 

1 

Q34 

KRC409 

74 

4 

R3,R53,R101 ,R102 

330 

75 

10 

R1,R4,R21,R43,R45,R49, 

R106,R107,R108,R141 

4K7 

76 

4 

R7,R20,R26,R33 

IK 

77 

3 

R8,R10,R40 

100 

78 

24 

R2,R5,R15,R19,R24,R30, 10K 

R31 ,R32,R34,R35,R38,R41, 

R52,R105,R112,R114,R126, 
R127,R128,R129,R131 ,R132, 

R152,R155 

79 

1 

R9 

3K3 

80 

3 

R11 ,R44,R54 

470 

81 

4 

R13,R22,R148,R159 

2K2 


82 


2 R14.R17 


0 



83 

2 

R16,R48 

47K 

84 

3 

R18,R123,R125 

470K 

85 

10 

R23,R29,R111 ,R122, R143, 
R147,R151 ,R154,R160,R174 

100K 

86 

2 

R25,R37 

220 

87 

1 

R28 

20K 

88 

1 

R39 

22 

89 

2 

R47,R55 

10 

90 

2 

R12.R103 

330K 

91 

1 

R104 

390K 

92 

2 

R109,R156 

1M 

93 

1 

R120 

120,0.5W 

94 

2 

R121,R136 

22K 

95 

1 

R124 

7K5 

96 

1 

R135 

12K 

97 

1 

R153 

82K 

98 

1 

R158 

2K7 

99 

1 

R171 

15K 

100 

1 

R172 

270K 

101 

1 

R173 

33K 

102 

2 

SF1 ,SF2 

446M 

103 

1 

SPK1 

36-16BB-08 

104 

2 

SW1 ,SW2 

KQT901 

105 

1 

T1 

T13 

106 

1 

TP 

TP 

107 

1 

U1 

HD40488-12B28TE(V4) 

108 

1 

U2 

CMX808A 

109 

1 

U3 

R1120N401B 

110 

1 

U4 

NJM386 

111 

1 

U5 

AK93C45AV-L 

112 

1 

U6 

NJM2072M 

113 

1 

U7 

NJM324V 



114 

1 

U8 

R1120N331B 

115 

1 

U11 

TB31202FN 

116 

1 

U12 

DBL5018V 

117 

1 

VC1 

3PM 

118 

1 

VC2 

10PM 

119 

1 

VR1 

10KM 

120 

1 

XI 

4MHz 

121 

1 

X2 

21.25MHz 

122 

1 

XF1 

MF21.7M3 

































































10. CHANNEL DATA (With Sub-channel data) 




















CTCSS (Continuous Tone Coded Squelch System) Frequency List 


Sub Channel 

Tone Frequency 

Sub Channel 

Tone Frequency 

1 

67.0 Hz 

21 

136.5 Hz 

2 

71.9 Hz 

22 

141.3 Hz 

3 

74.4 Hz 

23 

146.2 Hz 

4 

77.0 Hz 

24 

151.4 Hz 

5 

79.7 Hz 

25 

156.7 Hz 

6 

82.5 Hz 

26 

162.2 Hz 

7 

85.4 Hz 

27 

167.9 Hz 

8 

88.5 Hz 

28 

173.8 Hz 

9 

91.5 Hz 

29 

179.9 Hz 

10 

94.8 Hz 

30 

186.2 Hz 

11 

97.4 Hz 

31 

192.8 Hz 

12 

100.0 Hz 

32 

203.5 Hz 

13 

103.5 Hz 

33 

210.7 Hz 

14 

107.2 Hz 

34 

218.1 Hz 

15 

110.9 Hz 

35 

225.7 Hz 

16 

114.8 Hz 

36 

233.6 Hz 

17 

118.8 Hz 

37 

241.8 Hz 

18 

123.0 Hz 

38 

250.3 Hz 

19 

127.3 Hz 



20 

131.8 Hz 




© ALAN Electronics GmbH November 2001 
www.albrecht-online.de/service