Ranger_tr936966 Cb Tranciever_service Manual

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TR-936 
TR-966  
 TABLE OF  
CONTENTS 
 
 
 
 PAGE
CHAPTER 1  
SPECIFICATIONS  
1.0  General  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2 
1.1  Transmitter  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2 
1.2  Receiver  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

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TR-966 SPECIFICATIONS 
 
 
 
1.0 GENERAL  
Model  TR-936 / TR-966 
Frequency Range  26.965 ~ 27.405MHz. 
Emission Modes  TR-936 : AM. 
TR-966 : AM/SSB. 
Frequency Control  Phase Lock Loop (PLL) synthesizer. 
Frequency Tolerance 
± 0.005 % 
Frequency Stability 
± 0.001 % 
Operating Temperature Range 
-30°C to +50°C 
Microphone  Plug-in dynamic; with push-to-talk switch and coiled 
cord. 
Input Voltage 
13.8V DC nominal ±15%. 
Current Drain : Transmit  (AM full mod.)  

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Figure 2-1 Front Panel 
 
2.0 INTRODUCTION 
This section explains the basic operating procedures for the TEXAS RANGER TR-936 / TR-966 
mobile transceiver. 
 
2.1 CONTROL AND CONNECTIONS 
 
2.1.1 FRONT PANEL 
Refer to the above Figure 2-1 for the location of the following controls. 
 
1. MIC GAIN/ANF CONTROL    
Adjust the microphone gain in the transmit and PA modes. This controls the gain to the extent that full 
talk power is available several inches away from...

 - 4 - fully counterclockwise, and then turn clockwise until the background noise is just eliminated. Further 
clockwise rotation will increase the threshold level and only strong signals will be heard.  
 
4. RF GAIN CONTROL 
This control is used to reduce the gain of the RF amplifier under strong signal conditions. 
 
5. SWR CAL CONTROL 
This SWR CAL control allows the user to calibrate the SWR meter. 
 
6. S-RF/CAL/SWR SWITCH 
In the S-RF position, the meter will indicate the strength of the signal...

 - 5 - does not operate when you are in the PA mode. In the CB position, the PA function is disabled and 
the radio will transmit and receive on the speaker that is connected. 
 
CH19/OFF (TR-966) 
The Channel 19 switch is used for instant access to Channel 19, which is often used by truckers for 
transmission of traffic and weather conditions. 
 
13. R.B./OFF SWITCH (TR-936) 
In the Roger Beep position, the radio transmits an audio tone at the end of your transmission to 
indicate that transmission has...

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7OP

 - 7 - CHANNEL CHANNEL FREQUENCY 
(MHz) CHANNEL CHANNEL FREQUENCY 
(MHz) 
1 26.965 21 27.215 
2 26.975 22 27.225 
3 26.985 23 27.255 
4 27.005 24 27.235 
5 27.015 25 27.245 
6 27.025 26 27.265 
7 27.035 27 27.275 
8 27.055 28 27.285 
9 27.065 29 27.295 
10 27.075 30 27.305 
11 27.085 31 27.315 
12 27.105 32 27.325 
13 27.115 33 27.335 
14 27.125 34 27.345 
15 27.135 35 27.355 
16 27.155 36 27.365 
17 27.165 37 27.375 
18 27.175 38 27.385 
19 27.185 39 27.395 
20 27.205 40 27.405...

 - 8 - The receiver and transmitter are controlled by the push-to-talk switch on the microphone. Press the 
switch and the transmitter is activated, release the switch to receive. When transmitting, hold the 
microphone two inches from your mouth and speak clearly in a normal voice. The radio comes 
complete with a low impedance (500 ohm) dynamic microphone.  
 
2.3 OPERATION 
 
2.3.1 PROCEDURE TO RECEIVE 
1. Be sure that power source, microphone and antenna are connected to the proper connectors before...

 - 9 - For best results, the user should select a low impedance dynamic type microphone or a transistorized 
microphone. Transistorized type microphones have a low output impedance characteristic. The 
microphones must be provided with a four-lead cable. The audio conductor and its shielded lead 
comprise two of the leads. The third lead is for transmit control and the fourth is for receiving control. 
The microphone should provide the functions shown in schematic below (Figure 2-3).  
 
4 WIRE MIC CABLE...

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TR-966 DESCRIPTION  
 
 
 
3.0 INTRODUCTION 
This section explains the technical theory of operation for the Texas Ranger TR-936 / TR-966 mobile 
transceiver. 
 
3.1 PLL CIRCUIT 
The Phase Lock Loop (PLL) circuit is responsible for developing the receiver’s first local oscillator 
signal and the transmitter’s exciter signal. The PLL circuit consists primarily of IC2, IC3, Q25, Q27, 
Q28 and Q29. The PLL circuit is programmed by the rotary channel switch GPS-0501. The GPS-0501 
communicates the...