Kenwood MC-85

A desktop communications microphone that weighs a kilogram and packs a compressor, a level meter, and three-transceiver switching into one gooseneck-mounted package.

Overview

Pick up the Kenwood MC-85 and the weight hits you first - approximately 1 kg (2.2 lbs), which is a lot for a desk microphone. This is not a flimsy plastic computer mic. The silver and dark gray finish was designed to match Kenwood's communication equipment lineup, and the gooseneck mount lets the operator reposition the mic unit without moving the base.

The MC-85 is a unidirectional electret condenser microphone. The unidirectional pattern is the key spec. It rejects off-axis noise, and a radio shack has plenty of that: a transceiver fan, power supply hum, and whatever else is running in the room. The electret condenser element gives excellent high-frequency response. Voice comes through with a clarity that dynamic elements in the same price bracket often struggle to match.

The built-in speech compressor is what separates the MC-85 from a basic desk mic. Maximum compression is rated at 35dB ±3dB, and the compressor switches in or out with the MODE/POWER switch. For DX operation, pulling weak signals out of the noise, compression keeps average talk power up without overdriving the finals. The manual says the limiter circuit makes voice "heard more clearly," which is the whole point of running a compressor on SSB or FM.

The frequency response tells you what this microphone is for. In NORMAL mode, response runs 300-7,000 Hz. That is communications-grade response, rolled off at both ends to maximize intelligibility and minimize bandwidth. Switch to LOW CUT and the response drops approximately 12dB at 300Hz, thinning the low end further for situations where additional clarity is needed. The MC-85 is a tool for talking, not for recording voiceovers.

Sensitivity is rated at -40dB ±6dB with the compressor off and -34dB ±6dB with it engaged. Maximum input level is -30dB ±4dB. Those are the numbers you need when matching the mic to a transceiver's input stage. The 6dB boost from the compressor is significant, and operators report that the difference between COMP OFF and COMP IN is immediately audible on the receiving end.

The control surface is dense for a desk microphone. There is a PTT switch for momentary transmit and a separate LOCK switch for long transmissions - press once to transmit, press again to return to receive. Both light the PTT/LOCK LED in red when active. A POWER ON LED confirms the unit is running. A level meter on the body shows microphone output, which is useful for setting mic gain before a contact rather than guessing. The UP/DOWN switch ties into the transceiver's tuning functions and shifts frequency up or down. The manual notes that on transceivers without UP/DOWN tuning, the switch does nothing.

Two slide controls handle level management: one for mic gain and one for the built-in Audio Level Compensation circuit. The TONE switch selects between NORMAL and LOW CUT response. The output select switch is where things get interesting. The MC-85 ships with the output cable connected to position I, but with an optional PG-4 accessory, positions II and III become active, and the microphone can serve up to three transceivers. Few desk microphones offer that.

Power comes from four AA batteries, 1.5V each, 6V total. Batteries are not included, which was typical for the era. Current draw is modest: approximately 9mA in receive mode and 11mA in transmit. That means reasonable battery life, though the compressor and level meter will pull slightly more when active. The 1-meter output cable terminates in a standard 8-pin plug. A radio with a different mic jack needs an adaptor plug, and the manual provides internal wiring diagrams for anyone building their own cable.

The gooseneck holds the mic unit at whatever angle the operator sets, and it stays there. Cheap goosenecks sag under the weight of a heavy element. The MC-85's element is substantial, and the gooseneck is built to match. A windscreen is supplied, which helps with plosives and breath noise during close-in operation.

The MC-85 was designed for use with a wide range of communication equipment, and the manual is explicit about that. It is not tied to one transceiver model. The three-transceiver switching, the compressor, the level meter, and the UP/DOWN tuning integration all point to an operator running a serious station. The silver and dark gray color scheme matches Kenwood's communication lineup, so it looks right sitting next to a Kenwood HF rig or VHF/UHF transceiver.

The downsides are plain. The 300-7,000 Hz response is narrow by any audio standard, so anything other than communications will disappoint. The battery requirement means buying AA cells regularly or running rechargeables. The 8-pin connector limits direct compatibility with non-Kenwood equipment without an adaptor. And the optional PG-4 accessory for multi-transceiver switching is exactly that - optional, and likely difficult to find today.

Collectors and operators who own the MC-85 tend to keep it. The combination of the electret condenser element, the compressor, and the multi-radio switching makes it more capable than most desk mics of its era. It is not a rare piece, but it is a serious one — the kind of equipment that was bought by operators who knew what they needed and expected it to last. The 1 kg weight is not an accident; it is a statement about build quality.