TM 55-1510-221-10
3-10. VHF-AM COMMUNlCATlONS (VHF-206).
a. Description.
VHF-AM communications
provide transmission and reception of amplitude
modulated signals in the very high frequency range
of 116.000 to 151.975 MHz for a range of approxi-
mately 50 miles, varying with altitude. A dual head
control panel (fig. 3-4) is mounted on the pedestal
extension, accessible to both the pilot and copilot.
The panel. provides two sets of control indicators,
frequency indicators, frequency select knobs, a sin-
gle volume control, and a single selector switch for
quick frequency changing. Transmission audio is
routed by pilot and copilot No.1 transmitter selector
switches located on the audio control panel (fig.
3-1). Received audio is routed by pilot and copilot
No. 1 receiver audio switches (fig. 3-1), to the respec-
tive headsets. The VHF radio is protected by a 10-
ampere VHF circuit breaker on the overhead circuit
breaker panel (fig. 2-26). The associated antenna is
shown in figure 2-1.
b. Controls/Indicators and Functions.
(1.) Frequency indicator. Indicates set
operating frequency.
(2.)
Control frequency indicators. Indicates
frequency selected (left or right active).
(3.)
COMM TEST switch. Overrides auto-
matic squelch circuit.
(4.) Frequency selectors. Select desired set
operating frequency.
(5.) TRANS switch. Selects right or left
frequency control selectors.
(6.)
VOL-OFF control. Adjusts volume of
received audio, turns set ON or OFF.
c.
VHF-AM Set - Normal Operation.
(1.) Turn-on procedure: Volume control -
Turn clockwise (ON).
Change 4
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