Figure 3-7. HF Control Panel (718 U-5)
No. 4 radio monitor control (audio
control panel, fig. 3-1) Set to mid
Volume control (audio control
Squelch control (HF control panel) As
Frequency control (HF control
panel) Set desired frequency.
Transmitter operating procedure.
switch (audio control panel) No. 4
Function selector (HF panel) Set to
USB, LSB, or AM.
MIC HEADSET-OXYGEN MASK
switch (instrument panel) As desired.
SQL knob (HF panel) Adjust to just
quiet noise when no signal is being
MIC switch Depress to transmit.
3-14. HF COMMAND SET (718 U-5).
Description. The HF command set provides long-
range voice communications within the frequency range of
2.000 to 29.999 MHz and employs either standard amplitude
modulation (AM), lower side-board (LSB), or upper side-
board (USB) modulation. The distance range of the set is
approximately 2,500 miles and varies with atmospheric
conditions. The unit is protected by a 3-ampere HF RCVR
and the 25-ampere HF PWR circuit breaker on the overhead
circuit breaker panel (fig. 2-27). The control panel is located
on the pedestal extension.
Controls/Indicators and Functions.
HF Control Panel (pedestal extension, (fig.
Frequency selector. Selects the desired
Frequency indicator. Displays the selected
SQL control. Adjusts squelch level.