(4.) Transmitter operating procedure (CI-
(audio control panel, fig. 3-1) -
The HF system has two methods of frequency
selection. The first method is called direct tuning
(frequency agile). The second is a channelized opera-
tion in which desired operating frequencies are pre-
set, stored and referenced to a channel number.
Plain-cipher switch (voice security
panel) - CIPHER. (Indicator will
be illuminated while switch is in
b. Controls/Indicators and Functions (HF
Control Panel, jig. 3-7.
FREQ display. Displays frequency
3. RE-X-REG switch (voice security
panel) - As required. (Set RE-X
position only if distant station is
using re-transmitting equipment.)
momentarily (interrupted tone
from voice security unit should
no longer be heard.)
LSB, AM, or
CHANNEL display. Displays channel
Light sensor. The light sensor is a
photocell which adjust brigntness of the display.
MODE switch. The mode switch is a
momentary pushbutton switch that selects LSB, AM
No traffic will be passed if the interrupted
tone is still heard after pressing and
(6.) FREQ/CHAN switch. Transfers the
releasing the microphone switch.
HF system from a direct frequency operation to a
channelized form of operation.
Microphone switch - Press (do not
talk). Wait until beep is heard,
then speak into microphone.
(7.) PGM (Program) recessed switch.
Enables channelized data to be modified. The PGM
message will be displayed whenever this switch is
(5.) Shutdown procedure:
Mode selector switch (VHF
AM-FM panel) - OFF.
2. Power switch (voice security
panel) - OFF.
3-14. HF COMMUNICATION SET (KHF-950).
Description. The HF command set (fig. 3-7)
provides long-range voice communications within
the frequency range of 2.0 to 29.99 MHz and
employs either standard amplitude modulation
(AM), lower sideband (LSB), or upper sideband
(USB) modulation. The distance range of the set is
approximately 2,500 miles and varies with atmo-
spheric conditions. With the capability to preset and
store 99 frequencies for selection during flight, the
system also allows for selection of other frequencies
manually (direct tuning), or reprogramming of any
preset frequency. The system will automatically
match the antenna by keying the microphone. Power
to the system is routed through a 25 ampere circuit
breaker placarded HF PWR. The receiving portion
of the system is protected by a 5 ampere circuit
breaker placarded HF REC. Both circuit breakers
are located on the overhead circuit breaker panel.
The program mode must be used for set-
ting or changing any of the 99 preset fre-
quencies. Each of the 99 channels may be
preset to receive and transmit on separate
frequencies (semi-duplex), receive only, or
transmit and receive on the same fre-
quency (simplex). The operating mode
(LSB,USB or AM) must be the same for
both receive and transmit and can also be
(8.) Frequency/channel selector. This
selector consists of two concentric knobs that con-
trol the channel and frequency digits, plus the lateral
position of the cursor.
(a.) Frequency control. The outer
knob becomes a cursor (flashing digit) control with
the FREQ/CHAN switch in the FREQ position. The
flashing digit is then increased/decreased with the
Channel control. The outer knob
is not functional when the FREQ/CHAN switch is
in the CHAN position. The inner knob will provide