Radio station `` 20 RTP ''.

Receiving and transmitting radio equipment.The radio station "20RTP" (Swallow) has been produced since 1970. The portable radio station "20RTP" is a single-channel, simplex, transistor VHF radio station intended for the organization of a search-free, tuning-free telephone radio communication with the same type of radio stations operating at one of the frequencies in the range of 33 ... 46 MHz. The frequency spacing between channels is 25 kHz. Two-signal selectivity on the neighboring channel is 70 dB. The sensitivity of the radio receiver is 1 μV. The deviation of the transmitter frequency is 10 kHz. Supply voltage 7.5 V. The receiver is built on a superheterodyne circuit with double frequency conversion. The first IF is 7.612 MHz, the second is 0.5 MHz. For the 2nd IF, there is an EMFDP-500S-20.0 filter. The heterodyne is stabilized by quartz resonators. The ULF load is a loudspeaker 0.1 GD-3M, located in the body of the external headset and working as a microphone in the transmission mode. The transmitter is built according to the scheme with threefold frequency multiplication. The output stage is made on two parallel connected GT-311Zh transistors. Weight of the radio without carrying bag 0.95 kg. The radio station is used to organize communications in various sectors of the national economy, for construction sites, rail and road transport, for agriculture over short distances up to 1 ... 2 km. The power in the antenna is 100 mW. The rechargeable power supply unit consists of six accumulators of the TsNK-0.45 type, connected in series and is an integral part of the radio station. The "20RTP" radio station uses a 1.5 m long whip antenna of the Kulikov type.