Garmin GNC 420 Maintenance Manual page 62

5.6.1.5 Sidetone
The sidetone audio output level is independent of the COM volume knob on the unit.
The SIDETN field sets the sidetone audio output level. The sidetone can be set to any value
between zero and 63. The higher the number, the greater the sidetone volume.
SIDETN ___________ OK
5.6.1.6 MIC Gain
The MIC field sets the MIC audio gain. The MIC gain can be set to any value between 00 and
63. The higher the number, the greater the gain in the mic audio circuit.
MIC Gain ___________ OK
400 SERIES MAINTENANCE MANUAL
P/N 190-00140-05
Figure 5-3. R558 (Com Board)
Page 5-11
Rev. C