Galaxy DX 919, Owner'S Manual

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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. 

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Before beginning the actual wiring, read carefully the circuit and wiring information 

provided with the microphone you select. Use the minimum heat required in soldering 
the connections. Keep the exposed wire lengths to a minimum to avoid shorting when 
the microphone plug is reassembled. 
 
 

Fig. 2

 Microphone plug wiring 

 
 
 
To wire the microphone cable to the plug provided, proceed as follows: 
 
1.  Remove the retaining screw. 
 
2.  Unscrew the housing from the pin receptacle body. 
 
3.  Loosen the two cable clamp retainer screws. 
 
4.  Feed the microphone cable through the housing, knurled ring and washer as 

shown Figure 2.