Telex CS-90 Sportscaster Headset
A broadcast headset built for the sideline — boom mic, binaural cans, and a push-to-cough switch, all strapped to one frame.
Overview
The Telex CS-90 was sold as an all-in-one Sportscaster headset, and Telex's own advertising made the pitch plain: one piece of equipment that lets a broadcaster work a football field, a basketball court, or a golf course while staying hands-free. The company billed it as the combination of a professional broadcast-quality dynamic microphone with an equally high-performance headphone — the microphone on a boom, the headphone in binaural form. For a working sportscaster in the early 1970s, that was the whole argument in a single housing.
The microphone is the part that gets the most ink in Telex's copy. It's a wide-range dynamic boom design with a deliberately extended low-frequency response, which the company said was there to transmit the announcer's voice clearly and crisply. The same mic is omnidirectional, and that's not an accident — Telex wanted it to pick up crowd noise as well as the voice, so the audience at home got the atmosphere of the venue along with the call. DB-Magazine (January 1973, p.11) ran the product announcement describing exactly this arrangement: a live broadcast headset for fixed-station or mobile work that also lets the operator hear production cues and monitor his own transmission without tying up his hands.
The headphone side is a two-channel (binaural) design with a padded headband and foam-filled earcushions. Telex's later advertising describes those cushions as circumaural and claims they screen out nearby sound well enough that special acoustic facilities aren't necessary — a useful thing when you're calling a game from a crowded press box or the sideline. The drivers are what Telex called exclusive audiometric-type elements, a phrase that shows up repeatedly in the company's period ads and suggests the headphone lineage came out of its hearing-instrument work rather than its hi-fi line.
The CS-90's practical trick is the wiring. Telex built it with non-terminating cordage — unterminated leads — so the headset could be adapted to whatever the station or remote rig happened to use. Telex's own literature noted the binaural connection is made without termination so it can be adapted to the application, with one channel for monitoring and the other for cueing. That two-channel split is the whole point for broadcast work: one ear on program, the other on the producer.
Telex also built the thing to survive the job. The company's ads describe the headset as made of high-impact ABS plastic and stainless steel, chosen to stand up to constant moving, hard bumps, and weather extremes. That's marketing copy, but it lines up with the design brief: this is a headset meant to be worn on a moving body outdoors, not a studio piece that lives on a hook. The in-line "push-to-cough" switch — a mike-muting button on the cable — is the other concession to real-world use. It mutes the microphone when pressed, which is exactly what a sideline reporter needs when the ambient noise or a cough would otherwise go out over the air.
What the CS-90 is not is a hi-fi headphone, and Telex never pretended otherwise. The company's literature is aimed squarely at broadcasters, and the priority is intelligibility and cue monitoring, not flat frequency response for music listening. Collectors should treat it as a piece of broadcast hardware first and an audio curiosity second. The unterminated cable is the practical headache: a used CS-90 often arrives with bare leads or a connector someone soldered on decades ago, and the buyer is the one who has to figure out the pinout. The ABS-and-stainless construction tends to hold up, but the foam earcushions are the usual wear item on any headset of this age, and replacements in original form are not something Telex's current literature addresses.
Documentation on the CS-90 is thin by archive standards. The period advertising and the DB-Magazine product listings establish what the headset was and roughly when it was being promoted, but no production run, original price, or serialization data appears in the available sources. What's clear is the intent: a single headset that let a sportscaster roam, listen to cues, monitor his own voice, and mute the mic on demand — with the microphone and headphone engineered as one integrated tool rather than two pieces of gear lashed together.
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