====== Kenwood R-820 ======
Manufactured by [[Trio-Kenwood]].

In the late 1970s, Kenwood released the R-820, an excellent amateur band receiver that also covered a couple of shortwave broadcast bands.

{{:images:kenwood-r820.jpg?600|Kenwood R-820}}
===== Technical data =====
  * [[Principle]]: [[Double conversion superhet]], [[IF]] 8.83 MHz / 455 kHz
  * [[Operation modes]]: [[A1]], [[SSB]], [[A3|AM (A3)]]
  * [[frequency range]]: Amateur radio bands 160 - 10 m (in four sections); 49, 31, 25, 19 (WWV) and 16 m shortwave - broadcast bands.
  * [[Frequency display]]: Analogue dial, [[digital display]], 100 Hz.
  * [[Frequency memory]]: none
  * [[Signal strength indicator]]: [[S-meter]]
  * [[Signal processing]]: [[RF Gain]], IF Shift, [[ATT]] x 4, Variable Bandwidth, [[Notch Filter]], [[Noise Blanker]]
  * [[Features]]: 
  * [[Sensitivity]]: [[A3|AM (A3)]] / [[Selectivity]]: kHz (-6/-60 dB)

==== Power supply ====
  * [[Mains operation]]: 100, 110, 220, 240 V; 12 - 15 V =

==== Dimensions ====
  * 333 x 153 x 335 mm, weight 12 kg

==== Accessories ====
  * **SP-820** Loudspeaker
  * **AM-220** Station Monitor
  * **TS-820S** matching transmitter
  * **VFO-820** external VFO
  * optional IF filters YG-455CN, YG-455C, YG-88A

{{:images:kenwood-r820-front.jpg?600|Kenwood R-820, Front}}
===== Operation =====
With the R-820, Kenwood launched an amateur radio receiver in the late seventies, which, to the chagrin of shortwave listeners, did not have continuous coverage, but only covered the most important shortwave broadcast bands. The receiver not only had an analogue and digital frequency display, but also a variety of options for post-processing the shortwave signals.

The desktop unit with dimensions of 333 x 153 x 335 mm and a weight of 12 kg can be operated from the mains with 110 / 220 V and from approx. 12 V DC. On the rear panel is the SO 239 connector for the antenna and a multi-pin connector to connect the receiver to the matching TS-820S transmitter, with both components an amateur radio station is completed.

On the **front panel**, in the lower right corner, you will find the power switch and the switch for standalone - receiver operation and operation in conjunction with a transmitter.\\ 
Right next to it are the two band selector switches, with the right one the broadcast bands from 49 to 16 m are selected. In position NORM, the left switch selects the amateur radio bands, in position WWV (time signal transmitter on 15 MHz) the range covering the 19 m broadcast band is selected.

Above this are the rotary controls for the [[notch filter]], receiver fine tuning ([[RIT]]), "IF Shift" (to vary the [[PBT|passband]] of the [[IF filter]]) and the double potentiometer volume and [[RF gain]] control.\ 
Above you find the operating control for receive and transmit-receive mode, the bandwidth selector, which also has a function for continuous IF bandwidth and the [[preselector]].

In the centre is the tuning knob with a fine and coarse analogue dial and above it the digital frequency display.

To the left, next to the headphone and line out sockets, are the switches for the operation modes, the antenna attenuator and various switches for special functions such as the noise blanker, standby/receive and monitor (to monitor your own output signal.

{{ :images:kenwood-r820-back.jpg?400|Kenwood R-820, back}} With its various options to post-process a signal, the R-820 was one of the best semi-professional amateur radio receivers at the time of its release, even though its operation is not without any pitfalls due to the variety of special functions. The biggest limitation is the restricted coverage of only the amateur radio bands and a selection of broadcast bands. With continuous coverage of the entire shortwave spectrum, the receiver would probably have been even more successful. If you are looking for an amateur radio receiver, a second-hand R-820 in good working order is still a good choice.


===== Technical principle =====
Double conversion superhet covering mainly the ham bands.

==== Components ====
The set is solid state.

===== Technical documentation =====

==== Development ====
{{gallery>:images?kenwood-r820*.jpg&0&80x80&lightbox&showtitle&titlesort}}
==== Further information ====
  * [[https://www.radiomuseum.org/r/trio_kenwo_r_820_r820.html|Kenwood R-820 on the website of www.radiomuseum.org]]