Kenwood TS-820S

The Kenwood TS-820S is a model of amateur radio transceiver produced primarily by the Kenwood Corporation from the late 1970s into the 1980s; some were produced by Trio Electronics before Kenwood's 1986 name change). The transceiver's predecessor was the TS-520, which began production a year earlier. The TS-820S was the second of three hybrid models produced by Kenwood during the 1970s and 1980s. The TS-820S has a built-in power supply. The TS-820 did not have an LED frequency counter, but was otherwise identical to the 820S.

It can transmit and receive on the HF 10-, 15-, 20-, 40-, 80- and 160-meter bands, and can receive WWV and WWVH on 15 MHz. It can use SSB, FSK and CW on all bands. The TS-820S' power consumption is 57 watts (with heaters on) when receiving and 292 watts when transmitting. The transceiver's peak envelope power output on SSB and CW is about 100 watts, and about 60 watts on FSK. Its tubes are tuned manually, using the transceiver's drive, plate and load controls.

In reception this transceiver uses a single conversion heterodyne receiver that was quieter then the dual conversion of that of it's predecessor the TS-520. The TS-820S uses 3 tubes, 38 IC's, 31 FET's, 95 Transistors and 195 Diodes. The VFO is conventional and also uses a Phase Locked Loop(PLL) circuit in the local oscillator with an "IF" at 8.83 MHz.

The finals uses 3 tubes, a 12BY7A as the driver and two 6146B's. This combination produced a power input of 200W PEP on SSB, 160W DC on CW and 100W for FSK.