Beechcraft C-12C Operator And Technical Reference Manual page 301

(a) Direct Frequency Tuning (Simplex
Only).
1. FREQ / CHAN switch – FREQ.
2. Mode – Select desired mode,
USB, LSB, or AM.
3. Select digit to be changed (outer
knob), digit (cursor) will flash.
4. Select numerical value of digit,
inner knob.
5. Stow cursor, or repeat procedure
for additional changes.
6. Tune
microphone button.
(3) Channel Programming. There are three
ways to set up a channel: Receive only, simplex, and
semi-duplex. To gain access to channelized
operation, press FREQ / CHAN button to the CHAN
position. To utilize the existing programmed channels
(i.e. no programming required), use the inner control
knob to select the desired channel number.
momentarily key the microphone to tune the antenna
coupler. If channel programming is required, it is
necessary to activate the program mode as follows.
With the FREQ / CHAN button in, use a pencil or other
pointed object to push the PGM button in. The button
is an alternate action switch, push-on, push-off. The
letters PGM will appear in the lower part of the display
window and the system will remain in the program
mode until the PGM button is pressed again.
(a) Receive Only.
1. Stow the cursor if a frequency digit
is flashing.
2. Select the channel to be preset.
3. Set the desired operating mode,
LSB, USB or AM.
4. Set the desired frequency. Refer
to frequency tuning.
5. Push and release STO button
once.
T will flash in the display window, however,
a receive-only frequency is being set. The
flashing T should be ignored.
antenna coupler,
NOTE
If another channel is to be set, the cursor must
be stowed before a new channel can be selected. Use
the smaller concentric knob to select the channel and
repeat the steps for selecting a new frequency.
(b) Simplex.
simplex operation (receive and transmit on the same
frequency).
press
Then,
The first press of the STO button stores the
frequency in the receive position and the second press
stores the same frequency in the transmit position.
The second push also stores the cursor. If another
channel is to be reset, use the smaller concentric knob
to select the channel and repeat the steps for selecting
a new frequency.
stowed. To return to one of the operating modes,
push the PGM button again.
(c) Semi-Duplex. Setting a channel for
semi-duplex. Transmit on one frequency and receive
on another.
TM 1-1510-218-10
6. To return to an operating mode,
push the PGM button.
Setting a channel up for
1. FREQ / CHAN – CHAN, cursor
stowed.
2. PGM button – In.
3. Channel – Select.
4. Mode – Set LSB, USB, or AM.
5. Frequency –
frequency. Refer to frequency
tuning.
6. STO button – Push and release
twice.
The cursor was automatically
1. Channel – Select channel to be
preset.
2. Frequency –
frequency. Refer to frequency
selection.
3. Mode – Set LSB, USB, or AM.
4. STO button – Push once.
5. Transmit frequency – Set.
6. STO button – Push again.
Set desired
Set desired
3B-11