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- 12 -

PROCEDURE TO RECEIVE AND TRANSMIT 

 

A.

 

MICROPHONE 

The receiver and transmitter are controlled by the push-to-talk switch on the 

microphone. Press the switch and the transmitter is activated, release switch to 
receive. When transmitting, hold the microphone two inches from the mouth and 
speak clearly in a normal voice. This transceiver comes complete with a low 
impedance dynamic microphone.  
 

B.

 

PROCEDURE TO RECEIVE 

1.

 

Be sure that power source, microphone and antenna are connected to the proper 
connectors before going to the next step. 

 
2.

 

Turn unit on by running 

VOL

 knob clockwise on transceiver.  

 
3.

 

Set the 

VOL

 for a comfortable listening level. 

 
4.

 

Set the PA/CB switch to the CB mode.   

 
5.

 

Listen to the background noise from the speaker. Turn the 

SQ

 knob slowly 

clockwise until the noise just disappears. Leave the control at this setting. This 

SQ

 is now properly adjusted. The receiver will remain quiet until a signal is 

actually received. Do not advance the control too far or some of weaker signals 
will not be heard. 

 
6.

 

Set the 

CHANNEL

 selector switch to the desired channel. 

 
7.

 

Set the 

RF GAIN

 control fully clockwise for maximum receive gain. 

 

C.

 

RF POWER CONTROL 

This feature allows for the adjustment of the RF power output continuously over 
the range of 1 to 4 watts in AM. 
 

D.

 

PROCEDURE TO TRANSMIT 

1.

 

Select the desired channel of transmission 

 
2.

 

Set the 

MIC GAIN

 control fully clockwise. 

 
3.

 

If the channel is clear, depress the push-to-talk switch on the microphone and 
speak in a normal voice. 

 
 
 

 

- 13 -

ALTERNATE MICROPHONES AND INSTALLATION 

 

For best results, the user should select a low-impedance dynamic type 

microphone or a transistorized microphone. Transistorized type microphones have 
low output impedance characteristics. 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 fourth is for receiving control.  
 
The microphone should provide the functions shown in schematic below. 
 

4 WIRE MIC CABLE 

 

Pin Number 

Mic Cable Lead 

1 Audio 

Shield 

2 Audio 

Lead 

3 Transmit 

Control 

4 Receive 

Control 

 

 

 

Fig. 1

 Your transceiver microphone schematic. 

 

If the microphone to be used is provided with pre-cut leads, they must be revised 

as follows. 
 
1.

 

Cut leads so that they extend 7/16" beyond the plastic insulating jacket of the 
microphone cable. 

 
2.

 

All leads should be cut to the same length. Strip the ends of  each wire 1/8" and 
tin the exposed wire. 

 
 
 

Summary of Contents for DX-939

Page 1: ...rference 4 Antenna 4 Tuning The Antenna For Optimum SWR 5 External Speaker 6 Public Address 6 CHAPTER 3 Operation Control Functions 7 Front Panel 7 Rear Panel 10 Frequency Chart 11 Procedure to Receive and Transmit 12 Receiving SSB Signals 13 Alternate Microphone and Installation 15 Maintenance And Adjustment 18 A Few Rules That Should Be Obeyed 19 How Your CB Can Serve You 19 Use Channel 9 For Em...

Page 2: ...y strong Also provide a good electrical grounding connection to the chassis of the vehicle Proceed as follows to mount the transceiver 1 After you have determined the most convenient location in your vehicle hold the transceiver with mounting bracket in the exact location desired If nothing will interfere with mounting it in the desired position remove the mounting bolts Before drilling the holes ...

Page 3: ... a boat the transceiver will not operate at maximum efficiency without a ground plate unless the vessel has a steel hull Before installing the transceiver in a boat consult your dealer for information regarding an adequate grounding system and prevention of electrolysis between fittings in the hull and water 5 TUNING THE ANTENNA FOR OPTIMUM S W R Since there is such a wide variety of base and mobi...

Page 4: ...from the microphone to prevent acoustic feedback Physical separation or isolation of the microphone and speaker is important when operating the PA at high output levels 7 CHAPTER 3 OPERATION CONTROL FUNCTIONS FRONT PANEL 1 ON OFF VOLUME CONTROL Turn clockwise to apply power to the radio and to set the desired listening level 2 SQUELCH CONTROL This control is used to control or eliminate receiver b...

Page 5: ...matic Noise Limiter is activated In the NB ANL position the Noise Blanker is also activated The Noise Blanker is very effective in eliminating repetitive impulse noise such as ignition interference 13 PA CB RB SWITCH In the PA position your voice will come out of the speaker that you need to plug in to the PA SP jack on the back of the radio The radio does not operate when you are in the PA mode T...

Page 6: ...r is connected to this jack the built in speaker will be disabled 11 FREQUENCY CHART Channel Channel Frequency Channel Channel Frequency 1 26 965 MHz 21 27 215 MHz 2 26 975 MHz 22 27 225 MHz 3 26 985 MHz 23 27 255 MHz 4 27 005 MHz 24 27 235 MHz 5 27 015 MHz 25 27 245 MHz 6 27 025 MHz 26 27 265 MHz 7 27 035 MHz 27 27 275 MHz 8 27 055 MHz 28 27 285 MHz 9 27 065 MHz 29 27 295 MHz 10 27 075 MHz 30 27 ...

Page 7: ...r maximum receive gain C RF POWER CONTROL This feature allows for the adjustment of the RF power output continuously over the range of 1 to 4 watts in AM D PROCEDURE TO TRANSMIT 1 Select the desired channel of transmission 2 Set the MIC GAIN control fully clockwise 3 If the channel is clear depress the push to talk switch on the microphone and speak in a normal voice 13 ALTERNATE MICROPHONES AND I...

Page 8: ...cable before starting to solder If the washer is not captive to the pin receptacle body make sure that it is placed on the threaded portion of the pin receptacle body before soldering 7 If the microphone jack is used to hold the pin receptacle during soldering operation best results are obtained when the connections to pin 1 and 3 are made first and then the connections to pins 2 and 4 Use a minim...

Page 9: ... a conversation with another station for more than five minutes at a time without taking a one minute break to give others a chance to use the channel 2 You are not allowed to blast others off the air by over powering them with illegally amplified transmitter power or illegally high antennas 3 You can t use the transceiver to promote illegal activities 4 You are not allowed to use profanity 5 You ...

Page 10: ...out of gas on interstate 95 NO I am out of gas in my driveway YES There is a four car collision at Exit 10 on the Beltway send police and ambulance NO Traffic is moving smoothly on the Beltway YES Base to Unit 1 the Weather Bureau has just issued a thunder storm warning Bring the sailboat into port NO Attention all motorists The weather Bureau advises that the snow tomorrow will accumulate 4 to 6 ...

Page 11: ... RAN may be obtained from our website or by calling our Service Department at 760 480 8800 between 10 00 AM and 4 00 PM Pacific Time The RAN must be written below your return address on the outside of the shipping box Boxes which arrive without an RAN will be refused and the shipping company will return the unopened box to you Be sure to have a pen and paper ready along with the serial number of y...

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