5-7.3 Operating procedures. Radio operators must comply with FCC and Army radio communications procedures
when operating any radio. These procedures are available in FCC regulations, Army radio training materials and SSI/
SOI. They are not part of these instructions. The following paragraphs describe normal technical operations:
5-7.3.1 Army radio
Perform following to turn on Army radio:
Turn power supply (Figures 5-6 and 5-7) ac voltage selector switch to 115V, 50-60 Hz, 400-cycle
Turn power supply POWER ON/OFF switch to ON. Green ac ON indicator lamp should light.
Turn radio (Figure 5-8) BREAKER-RESET power switch to LOW.
Set radio LIGHT selector switch to ON so that LAMP and CALL control indicators light.
Do not use following frequencies because they will cause improper operation of
Army radio: 33.90 Hz, 45.20 Hz, 56.50 Hz, and 67.80 Hz. Do not use frequencies
that are separated exactly by 5.75 Hz or 23.00 Hz.
On Army radio (Figure 5-8), perform following to receive transmissions from another Army radio station:
Radio operator must obtain assigned frequencies (primary and alternate), network,
and call signs for barge radio and other stations to be contacted. Frequencies, call
signs, and network organizations are obtained from SSI/SOI. Unit headquarters
provide extracts of SSI and SOI.
Turn BAND selector switch to either A or B position for desired frequency band.
When using SQUELCH control, radio background noise is silenced when
transmitter is not keyed. Newer model FM radio sets use a squelch control which
automatically disables radio squelch circuitry. For reliable communications, make
sure that both distant radio stations and barge and workboat radio squelch
controls are in same position, i.e., NEW ON or OLD ON. If unsure of distant station
squelch control setting, initially tune with squelch in either OFF position.
For SQUELCH operation, turn SQUELCH control to either NEW ON or OLD ON, as appropriate.
Turn MC TUNE control to desired MHz frequency. MC TUNE control provides manual tuning of
radio in 1 MHz steps as indicated by outer section of dial window.
Turn KC TUNE control to desired kHz frequency. KC TUNE control provides manual tuning of
radio in 0.05 Hz steps as indicated by inner section of dial window.
Turn SPEAKER selector switch to ON position and adjust to a comfortable listening level.
On Army radio (Figure 5-8), perform following to transmit to a radio station on your frequency in your radio
If there are problems with Interference, have IDS/IGS maintenance check
interfering frequency charts to make sure interference-free frequency is being