Kenwood MC-50 (c. late 1970s–1980s)

Name: Kenwood MC-50
Brand: Kenwood

The MC-50 is a desk microphone, not hi-fi gear. It was built for amateur radio, and Trio-Kenwood's own manual says so plainly: it was designed for ham operation and to match the company's amateur equipment. Anyone browsing the audio section for a tuner or an amp will be surprised. This is a communications microphone with a push-to-talk circuit, meant to sit on a radio shack desk and key a transmitter.

The element is a moving-coil, unidirectional (cardioid) type with dual impedance ratings, selectable between Hi-Z (50 kΩ) and Lo-Z (600 Ω) at 1 kHz, both rated ±30%. Sensitivity is quoted as −56 dB at 50 kΩ and −76 dB at 600 Ω (0 dB = 1 V/µbar at 1 kHz). Frequency response is 150 Hz to 10 kHz at −6 dB. The manual recommends operating no closer than about 10 cm (4 inches) from the mic.

The base is die-cast zinc. Per the manual, that was a deliberate choice to give it enough weight to stay put "even at contest speeds." Switching is handled by two "piano key" style keys on the base. One is push-to-talk, and one is a lock that holds the transmitter on until pressed again. There's a slide switch for PTT as well, but it's inoperative when the mic is base-mounted, so you use the keys instead. Impedance is selected at the connector. The mounting connector carries a red "H" and black "L" marker, and you align the coil-cord connector to whichever you want. There's one alignment procedure for hand-held use and another for base-mounted. The coil cord terminates in a 5-pin female connector for the base and a 4-pin female connector for the transceiver.

Surviving documentation for the MC-50 is essentially the manual and not much else. The period audio press doesn't help. The magazine chunks that surfaced for this model are unrelated: an Audio (October 1978, p.71) page listing a Kenwood KA-9100 amplifier alongside a Marantz 1300DC and Hitachi HMA-8300, and a couple of classified-ad pages from Audio (August 1982, p.76) and Mix-Magazine (January 1981, p.51) with no MC-50 content at all. There is no review, no measured test and no contemporary price. It was a ham accessory that lived outside the hi-fi review pipeline.

What's known, in short:

Dynamic communications microphone with push-to-talk circuit
Moving-coil, unidirectional (cardioid) element
Dual impedance: 50 kΩ (Hi-Z) / 600 Ω (Lo-Z), ±30% at 1 kHz, connector-selectable
Sensitivity: −56 dB (50 kΩ), −76 dB (600 Ω), ref. 0 dB = 1 V/µbar at 1 kHz
Frequency response: 150 Hz–10 kHz (−6 dB)
Die-cast zinc base; two "piano key" switches (PTT and lock)
Recommended operating distance: 10 cm (4 in) minimum

Exact production years aren't documented in the material available. The manual is printed in Japan and distributed by Trio-Kenwood Communications, Inc., with regional distribution noted for Australia (Trio-Kenwood Australia Pty. Ltd., Artarmon, N.S.W.) and Germany (Trio-Kenwood Communications GmbH). A dated example or a period catalogue listing would fill a real gap.