The radio receiver “PR-4-P” became a post-war modernization of the “US” receiver, which was developed around 1935 for military aviation.
This is a universal receiver for receiving telephony, voice-frequency telegraphy and telegraphy with undamped oscillations. It was used as part of RSB radio stations of all modifications, RAF, RSR-1 and others.
Superheterodyne with one 112 kHz IF frequency conversion. The receiver range provides the ability to receive radio signals at frequencies from 175 to 12000 kHz (1714 – 25 m).
The entire range of the radio receiver is divided into 5 sub-ranges:
1 subband 175 – 350 kHz;
2 subband 375 – 875 kHz;
3 subband 900 – 2150 kHz;
4 subband 2150 – 5000 kHz;
5 subband 5000 – 12000 kHz.
On subbands 1 and 2, the frequencies are indicated in the table on the front panel of the radio; on 3, 4, and 5 subranges – are applied directly to the scale. There is no graduation on the sub-bands “I” 173-350 kHz and “II” 350-875 kHz, it is replaced by an exact scale broken into 180 degrees.
