Kenwood 820S

A ham-band transceiver whose documentation survives in fragments, and whose identity the archive cannot yet pin down with confidence.

Overview

The Kenwood 820S is a hard entry to write, so this page starts with the honest version. The archive's research payload for this model came back empty. There is no fact sheet, no verified identity details, no production years, no original price and no confirmed specifications. What exists is a body of manufacturer documentation attributed to the 820S that, read closely, describes a different machine. There is also a set of period magazine chunks that mention "820" in contexts that have nothing to do with a Kenwood transceiver. Both are worth walking through, because the thin record is the story here.

Start with the manual excerpts. Ten chunks were indexed from a PDF attributed to the 820S. They describe a single-conversion HF transceiver with a PLL local oscillator and 8.83 MHz crystal filters, which is the architecture of the Kenwood TS-820, a well-known ham rig. The manual text names the TS-820 in several places. The frequency diagram is captioned "Fig. 3 TS-820 frequency diagram," the power consumption note reads "TS-820 is used," and a modification section is headed "TS-820 MODIFICATION FOR MARINE BAND (2.134 MHz)." The document also describes a VFO-820 external unit that draws its power from the TS-820 (12.6 VAC at 40 mA, 12.6 VDC at 40 mA, and 9.0 VDC at 25 mA). It measures 6.5 inches wide by 6.0 inches high by 7.5 inches deep excluding feet, and weighs 6.6 lbs with a shipping weight of 8.36 lbs.

That is a real problem for attribution. The chunks are tagged as belonging to the 820S, but the text inside them belongs to the TS-820 and its VFO-820 companion. Whether "820S" is a variant, a regional suffix, a mislabeled scan or something else can't be determined from the material available. The archive flags this rather than papering over it. Treat every specification in those excerpts as belonging to the TS-820 family until documentation naming the 820S turns up.

For whatever it's worth as family context, the TS-820 documentation shows a fairly sophisticated HF design. The transceiver uses a single conversion scheme with an 8.83 MHz IF, and the mode table gives carrier oscillator assignments for LSB at 8828.5 kHz, USB at 8831.5 kHz, and CW at 8830.7 kHz, among others. Band coverage runs from the JJY/WWV time station slot through 1.8, 3.5, 7, 14, 21, 28, and 28.5 MHz, with VCO ranges and heterodyne frequencies tabulated for each. An RF speech processor converts the audio signal up to 455 kHz for compression processing. The manual contrasts this with conventional clipper systems and claims reduced distortion and better preserved tone quality. A built-in monitoring circuit lets the operator hear their own transmitted signal through the 8.83 MHz crystal filter, product-detected by an FET and fed through the AF AVR stage. It is energized only during SSB transmission.

The digital display section is unusually detailed in the manual. It reads transmit and receive frequencies using carrier, VFO, and local oscillator signals rather than converting VFO frequencies, so accurate readouts are available on any band and in any mode. Accuracy is set by a single 1 MHz standard oscillator, and the manual notes that calibrating against WWV allows readings to 100 Hz order. The display is green, which the documentation claims "assures many hours of fatiqueless operation." The typo is in the source, so it stays.

The RF design also gets a chapter. The TS-820 applies negative feedback to a tuned-type amplifier circuit including interstage LC tuned circuits. The manual acknowledges this is difficult to do stably because of parts arrangement and frequency response constraints. The design is specified to avoid undesired oscillation even when gain rises to three times optimum. Neutralization uses variable capacitors with floated rotors and stators, which the manual claims achieves the same effect as μ tuning type neutralization. Variable-capacitor neutralization is generally considered harder to get right across an all-band transceiver.

Now the magazine chunks, which are a different kind of problem. Six period chunks were indexed for the 820S, and not one of them discusses a Kenwood transceiver. The first is a car stereo column from *HI-Fi-Stereo Buyers* (May 1980, p.33) covering trends from the Consumer Electronics Show - automation, miniaturization, hi-fi quality in dash units. The second is an High Fidelity (May 1975, p.40) equipment review of the Elac Miracord 820, a two-speed record changer priced at $129.95 with an optional oiled walnut base at $20.95 and dust cover at $16.95. The third is a *High Fidelity* (June 1982, p.14) news item about a low-price Sonus product for high-mass tonearms. The fourth is an *Audio* (March 1996, p.92) dealer showcase listing a Waldorf Astoria show room numbered 820. The fifth is a *Recording-Engineer* (October 1987, p.56) exhibitor booth list from the Sheraton Centre with a row of numbers including 821 and 822, and no Kenwood content. The sixth is a *HiFI-Stereo* (August 1982, p.12) letters page with a note from the Library of Congress music cataloging section.

Every one of these chunks matched on the string "820" and nothing more. None of them is about the Kenwood 820S. The Elac Miracord 820 is a record changer, and the Kenwood 820S is not. The room 820 at the Waldorf is a hotel room. The booth numbers at the Sheraton Centre are booth numbers. Citing any of these as period reception for the Kenwood 820S would be fabrication, and the archive won't do that.

That leaves a collector trying to identify an 820S with three plausible readings and no way to choose among them from the available material. The first is that the 820S is a TS-820 variant, perhaps a suffix denoting a specific market, a revision or a bundled configuration, and the manual scan was filed under the wrong designation. The second is that "820S" is a transcription error somewhere upstream, and the model never existed under that exact name. The third is that a distinct 820S exists and simply has no documentation in this archive yet.

None of these can be resolved with what's on hand, and the archive says so rather than build a plausible-sounding story. Anyone who owns a unit badged 820S, or who has a service manual, owner's manual or period advertisement naming the model, can contribute it. Until then the documentation attributed to the 820S describes the TS-820, the period sources describe other products, and the identity of the 820S itself remains unconfirmed.