TM 55-1510-221-10
steps for selecting a new frequency. The cursor was
automatically stowed. To return to one of the oper-
ating modes, push the PGM button again.
(b.) Semi-duplex operation: Setting a
channel for semi-duplex (transmit on one frequency
and receive on another).
1.
Select channel to be preset.
2. Set desired frequency. (Refer to
frequency selection)
3.
Set mode (LSB,USB, or AM).
4. Push STO button once.
5. Set transmit frequency.
6. Push STO button again.
If another channel is to be reset, use the smaller
concentric knob to select the channel and repeat the
steps.
7. To return to an operating mode,
push the PGM button.
NOTE
The mode for each channel (LSB, USB or
AM) is stored along with the frequency. If
the mode is changed, the system will
receive and transmit in the mode selected
for transmit.
d.
Shutdown. Off/Volume switch - OFF.
e.
HF Command Set - Emergency operation.
Not applicable.
3-15. EMERGENCY LOCATOR TRANSMITTER
(ELT).
a. Description. An emergency locator trans-
mitter is provided to assist in locating an aircraft
and crew in the event an emergency landing is
necessitated. The output frequency is 121.5 and 243
MHz simultaneously. Range is approximately line-
of-sight. The transmitter unit has separate function
control switches located on one end of the case. In
the event the impact switch has been inadvertently
actuated, the beacon can be reset by firmly pressing
the pushbutton RESET switch on the front of the
case. The RESET switch and a 3-position toggle
switch, placarded ARM, OFF and ON, also on the
transmitter case, may be actuated by inserting one
finger through a small, round, spring-loaded door on
the left side of the aft fuselage (fig. 3-8). The trans-
mitter unit is accessible through a service panel
located on the bottom of the aft fuselage.
b. Controls and Functions.
(1.) RESET switch. When pressed, resets
transmitter.
(2.) Function switch. Selects operating
mode of set.
(a.) ARM. Arms set to be actuated
by impact switch (normal mode).
(b.) OFF. Turns set off.
(c.) ON. Manually activates trans-
mitter for test or emergency purposes.
3-18
