Army shortwave local paging receiver, part of SVITAVA system. The system worked at shortwave around 2MHz, there was a simple time-alternating sequence of 2 of 7 tones used for selective call (thus, about 40 combinations). The system used amplitude modulation for both tone sequence and voice messaging.

Upon reception of paging sequence, the receiver starts beeping with no time limit (thus, it can beep very long if call not accepted manually), after the acceptation of a call by control button it switches to plain AM reception to allow listen to the voice message.

The charging stand allows the usage of an external antenna to improve the reception. There was no time limit in charging of the accumulators (2 x NiCd button cell 225mAh).

This is an "field" version of R01A "indoor" receiver. R01M uses hybride IC technology in spite of the indoor version.

Listen to the activation signal (reverse engineered) and the original sound clip.

All photos are © OK1UHU, 2011