User's Guide

FREQUENCY SELECTION
AND DISPLAY
Please note that the international aircraft standard is used in the
frequency selection and frequency presentation of the 0.5 kHz
frequencies. That is:
154.320 reads 154.320
154.3225 reads 154.322
464.325 reads 464.325
464.3275 reads 464.327
CONTROL OPERATION
The following describes the operation of each operator accessible
control knob, switch or indicator:
!
PRESET CHANNEL SELECTORS: Allows selection of 30
channels of pre-programmed frequencies, tones and Channel
Memory Discretes.
!
TEST/LOAD Switch: Disables the receiver squelch, also,
when activated simultaneously with the Preset switch, loads
preset frequencies, tones and five Channel Memory Discretes.
!
PRESET - RCV/XMT Switch: Used in conjunction with the
LOAD/TEST Switch, selects either receive or transmit half of
channel memory. Activates seven segment frequency and
tone LED displays.
!
MAIN RECEIVER Squelch Lamp: Indicates signal on Main
Receiver. Dims automatically.
!
GUARD RECEIVER Squelch Lamp: Indicates signal on
Guard Receiver. Dims automatically.
!
ON/OFF/VOLUME Control
!
TONE - ON/OFF/MNL Switch: Allows manual selection of
transmitted tone by way of thumbwheel TONE selectors in
MNL position, allows Main and Guard tone squelches to
operate in the ON position, and allows Main and Guard
receiver tone squelches to be disabled in either the MNL or
OFF positions. In either the OFF or MNL positions the
receiver's squelches operate via their noise squelch circuitry.
!
T/R SELECT Switch -MAIN/BOTH/GUARD: In the MAIN
position - enables the Main Receiver only and transmits on
the main channel selected. In the BOTH position - enables
both the Main and Guard Receivers and transmits on either
the main or guard channel (dependent on the XMTR-MN/GD
switch); in the GUARD position - enables only the Guard
Receiver and transmits on the selected guard channel.
!
XMTR - MN/GD Switch: Selects either main channel or
guard channel during transmitter operation only if the
T/R-MAIN/BOTH/GUARD switch is in the BOTH position.
!
XMTR Lamp: Indicates transmitter operating, dims
automatically.
!
RPT/DIR Switch: Selects transmitter to operate on different
frequency than receiver (RPT) or same frequency as receiver
(DIR) during main channel operation. Selects one of two
guard channels during guard channel transmitter operation
and during guard transmit channel programming.
!
FREQUENCY and TONE Selectors: Internally lighted
thumbwheels used in manual selection and programming of
frequencies and tones. Lighting may be disabled by means of
an internal switch.
!
N/W SWITCH: Selects either Narrow or Wide Band
operation. When N is selected and the channel selector
switch is on M, an LED lights in the lower right corner of the
kHz display. The LED also lights when a preset memory
channel has been programmed for narrow band.