Figure 5-13. Com Setup Page (Gnc 420 And Gns 430 Only) - Garmin GNC 420A Installation Manual

5.2.11 COM SETUP Page (GNC 420 and GNS 430 Only)
Select the COM SETUP Page (see Figure 5-13). These
values are set at the factory and seldom require calibration.
FREQ
Selects a VHF communication frequency. For purposes of
setting the squelch and sidetone levels, only the
frequencies 118.000, 127.000, and 136.975 MHz can be
used.
SPACING
Selection
25.0 kHz
8.33 kHz
8.33 kHz channels are not authorized for use in the United States.
SQ 250
Sets the squelch threshold for 25 kHz channel spacing operation. May be set to any value between 0 (zero)
and 63. The higher the number, the less signal is required to break squelch.
For GNS 430 units with serial number 200 or lower, the operation of the SQ 250 setting is reversed. The
higher the SQ 250 number, the more signal is required to break squelch.
SQ 833
Sets the squelch threshold for 8.33 kHz channel spacing operation. May be set to any value between 0
(zero) and 63. The higher the number, the more signal is required to break squelch.
SIDE
Sets the sidetone audio output level. May be set to any value between 0 (zero) and 63.
MIC
Sets the Mic Gain output level. May be set to any value between 0 (zero) and 63. This adjusts the output
for differences in microphones used. Should adjustment be necessary refer to the maintenance manual.
This Mic Gain software adjustment is effective for GNS 430 s/n 97107371 and above, and GNC 420 s/n
97202086 and above.
The sidetone audio output level is independent of the COM volume knob on the 400 Series unit.
Store Calibration?
Select this field and press the ENT key to accept the squelch threshold and sidetone audio settings on this
page. If you wish for the squelch and sidetone settings to return to their previous values, do not select this
field. Simply change to the next configuration page, or turn off the unit if you are done with configuration.
Selection
PTT
XFR
RX
TX
Page 5-10
Page Rev L
Description
Selects traditional 25 kilohertz spacing (760 channel).
Selects 8.33 kilohertz channel spacing, which is required in some areas of the
world.
CAUTION
NOTE
NOTE
Verify That:
The box is filled in while the COM push-to-talk switch is pressed.
The box is filled in while a remote COM transfer switch is pressed.
The box is filled in while the COM is receiving a signal.
The box is filled in while the COM push-to-talk switch is pressed.
Figure 5-13. COM SETUP Page
400 SERIES INSTALLATION MANUAL
P/N 190-00140-02