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Thus when a voice is used in place of a whistle or tone, in the proper listening mode 

the voice will be received correctly whereas in the incorrect mode, the voice will be 
translated backwards and cannot be made intelligible by the CLARIFIER control. 
When listening to an AM transmission, a correct side band is heard in either mode 
since both upper and lower side bands are received. 
 

Once the desired SSB mode has been selected, frequency adjustment may be 

necessary in order to make the incoming signal intelligible. The CLARIFIER control 
allows the operator to vary frequency above or below the exact frequency of the 
channel. If the sound of the incoming signal is high or low pitched, adjust the 
operation of the CLARIFIER. 
 

Consider it as performing the same function as a phonograph speed control. When 

the speed is set too high, voices will be high-pitched and if set too low, voice will be 
low-pitched. Also, there is only one correct speed that will make a particular record 
produce the same sound that was recorded. If the record is played on a turntable that is 
rotated in the wrong direction (opposite side band) no amount of speed control 
(CLARIFIER) will produce an intelligible sound. 
 

An AM signal received while listening in one of the SSB modes will produce a 

steady tone (carrier) in addition to the intelligence, unless the SSB receiver is tuned to 
exactly the same frequency by the CLARIFIER control. For simplicity, it is 
recommended that the AM modes be used to listen to AM signals. 
 

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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 the 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 979

Page 1: ...io 3 Ignition Noise Interference 4 Antenna 4 External Speaker 4 Public Address 4 CHAPTER 3 Operation 5 Front Panel 5 Rear Panel 8 Frequency Chart 9 Procedure to Receive and Transmit 10 Receiving SSB Signals 11 Alternate Microphone and Installation 13 Maintenance And Adjustment 16 A Few Rules That Should Be Obeyed 17 How Your CB Can Serve You 17 Use Channel 9 For Emergency Message Only 18 ...

Page 2: ...nstallation of the radio Hold the mounting bracket with the radio in the location where the radio is to be installed Make sure nothing will interfere with either the radio or the mounting bolts Mark and then drill holes for the mounting bracket 2 Most radio antennas come equipped with a PL 259 plug Connect this plug to the ANT Jack in the rear of the radio 3 Extending from the rear of the radio is...

Page 3: ...en the external speaker is plugged in the internal speaker is disconnected PUBLIC ADDRESS To use the Public Address PA function first connect an external speaker to the PA SP Jack on the rear of the radio See the above specifications for a proper external speaker Keep the speaker away from the microphone to avoid acoustic feedback 5 CHAPTER 3 OPERATION CONTROL FUNCTIONS FRONT PANEL 1 MICROPHONE JA...

Page 4: ...ows tuning of the receive frequency above or below the channel frequency by up to 1 0KHz Although this control is intended primarily to tune in SSB signals it may be used to optimize AM signals 14 SWR MOD PWR SWITCH This switch controls the function of the meter during the transmit mode In the SWR position the meter indicates the Standing Wave Ratio SWR of your antenna There are no adjustments bec...

Page 5: ...EL NO DX 979 CB TRANSCEIVER AM SSB 40 CH DATE OF MFG FCC ID MEE DX 979 SERIAL NO 1 ANT 2 DC 13 8V EXT SP F C PA SP 3 4 5 This device complies with part 15 of the FCC Rules Operation is subject to the condition that this devicedoes not cause harmful interference Service Manual at www GalaxyRadios com 9 FREQUENCY CHART Channel Channel Frequency Channel Channel Frequency 1 26 965 MHz 21 27 215 MHz 2 ...

Page 6: ...will detect upper side band and lower side band respectively and standard AM signals SSB reception differs from standard AM reception in that an SSB receiver does not require a carrier or opposite side band to produce an intelligible signal A single side band transmitted signal consists only of the upper or the lower side band and no carrier is transmitted The elimination of the carrier from the A...

Page 7: ...o amount of speed control CLARIFIER will produce an intelligible sound An AM signal received while listening in one of the SSB modes will produce a steady tone carrier in addition to the intelligence unless the SSB receiver is tuned to exactly the same frequency by the CLARIFIER control For simplicity it is recommended that the AM modes be used to listen to AM signals 13 ALTERNATE MICROPHONES AND ...

Page 8: ...the plug Fig 3 Microphone plug pin numbers viewed from rear of pin receptacle 6 Be sure that the housing and the knurled ring of Figure 2 are pushed back onto the microphone 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 t...

Page 9: ...supervision of the holder of an FCC issued general radio telephone operator s license 14 17 A FEW RULES THAT SHOULD BE OBEYED 1 You are not allowed to carry on 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 amp...

Page 10: ... am out of gas on interstate 95 NO I am out of gas in my driveway YES There is a four car collusion 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 t...

Page 11: ...MEMO MEMO ...

Page 12: ...umber RAN This 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 seri...

Page 13: ...Printed in China AT0919030A ...

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