The AN/ARC-164 provides two-way UHF amplitude modulate (AM) narrow band voice communications within the frequency range of 225.00 to 399.95 MHz on 3500 channels for a distance of approximately 50 miles as limited by conditions. A guard receiver is incorporated in the set and is fixed tuned to 243.00 MHZ. Both receivers are disabled during transmitter operation.  The radio set control panel is marked UHF.  The UHF radio transmitter and main receiver operate on the same frequency and are simultaneously tuned by frequency selector knobs on the panel.  When the function selector switch is placed in the T/R GUARD  (AN/ARC-116) or BOTH UHF guard frequency (243.00 MHz) is possible regardless of main receiver-transmitter frequency selected.  The set utilizes selector switch 6, position number 2 of the interphone control panel.

The UHF set is used for transmission and reception.  The audio signal level is adjusted by the volume control and the signal is then applied to the interphone control panels for selection.  When the No. 2 receiver switch is on, the audio signal lever is further adjusted by the interphone control panel volume (VOL) control and is fed to the headset.  When the No. 2 transmit position is selected and the microphone output is amplified in  the audio control panel and applied to the UHF command transmitter.  Side tone audio is routed back to the headset in the same way as receiver audio.