Soviet MF/HF receiver type USP

The Soviet USP was a receiver for reception of transmissions in the MF and HF bands. It was used by the Soviet Army at Corps and Division as a mobile or fixed station principally with radio station RSB and RAF-KW. The USP version differed slightly from the initial World War 2 type US.

• Frequency coverage 175kHz to 12 MHz in five ranges.
• A BFO and RF gain control are provided for reception of CW signals.
• The IF is 112 kHz.
• Circuit comprises an RF amplifier (6K7), mixer (6A8) and separate local oscillator (6k7). This is followed by two IF amplifier valves (6K7), detector AVC (6H6) and AF amplifier (6K7). BFO valve is an 6K7.
• Sensitivity 1-4 microvolt (A1) and 2-10 microvolt (A3).
• Supply unit RU 11B provides 200V at 50mA.
• The AF output is at headphones level.

Transmitter RSB-F and receiver type US along with supply units fitted in transit case.