Alternate Microphones And Installation - Galaxy DX 979 Owner's Manual

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.
- 12 -

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
1
2
3
4
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.
Mic Cable Lead
Audio Shield
Audio Lead
Transmit Control
Receive Control
- 13 -