2-4. OPERTING PROCEDURES. (CONT)
TWO-WAY VOICE COMMUNICATION
1. Turn on aircraft communications equipment in accordance with starting procedures.
2. Set control unit mode control switch (1) to T/R.
Some older control units may contain a mask which covers the TONE squelch mode on
the SQUELCH mode selector switch. If this is the case, it could be possible that the radio
set is not capable of tone squelch operations. At a time not to interfere with the mission
or aircraft, have radio set checked and updated as required.
3. Set SQUELCH mode selector switch (2) to desired squelch mode.
A channel-changing tone should be heard in the headset while the radio set is tuning.
When tone stops, radio set is tuned.
5. After a 20-second warmup, depress aircraft push-to-talk button (location varies according to
aircraft type and crew position) and talk into microphone. Note that side tones are heard in
6. Adjust VOL control (4) for comfortable volume.