1985: Telos 10 Debuts DSP to NAB

By Art Reed on Apr 9, 2014 9:16:00 AM

Art ReedThe central focus of the Bradley Broadcast booth in 1985 was the Telos 10.

How we got there – and what happened during those four days – was unlike any other trade show I’ve attended.

But first, some background.

Steve Church told me in 1984 that he developed the Telos 10 after spending many nights in the library reading AT&T labs reports about their research and experiments with “sidetone removal” and the equipment they built to test it out. He credited them with the “discovery” of the technology of the digital telephone hybrid, but that, once discovered, they didn’t really have any use for it.

Sidetone in telco conversations is a feature, not a bug, given that it provides feedback to the phone user that his voice is being heard on the phone line. Thus, full separation of send and receive audio via telephone was not a major goal for AT&T. Steve also noted that, in order to implement the technology, AT&T required “a rack full of equipment” that cost tens of thousands of dollars, further arguing against its use in their telephone infrastructure.

Once Steve had absorbed the concepts of the AT&T research, he hand-wrote the code on legal pads. The original Telos 10 had the code burned directly into the DSP chip. Steve told us that he burned, tested and rejected eight or nine chips on the original Telos 10 (at over $200 each) before he was satisfied with the result, each time, going back to the legal pad to make changes to the code. After each “failed” burn, he had to discard the now-useless chip. It was obvious from his telling of the story that it went against his natural frugality to know he had to spend that much to make the code right.

Through the rest of 1984 and into 1985, we talked to Steve regularly about getting the Telos 10 into production as a product, and trying to sell some units. Steve had manufactured several units on his kitchen table, and sold them to friends in the radio business, but this was done on a personal basis. We didn’t get much traction out in the broadcast marketplace, as few people had heard of Steve, no one even knew what adaptive filtering was, and we didn’t have access to any units to demonstrate.

Steve was skeptical about the long-term success of the unit. “This is a specialized product” he would say, “and very expensive. Only a few of the larger stations will be able to afford one, and after they have bought theirs, will there be any demand for the product? Will stations really spend $3,100.00 for this?”

This all changed in April of 1985.

NAB 1985

The small 10x10 booth Bradley Broadcast occupied in the back of the hall would have been doomed to obscurity had it not been for the Telos 10.

We had purchased a tall Anvil case, and populated it with two ElectroVoice ELX-1 mic mixers to create a mix-minus, and an EV Sentry 100 powered speaker to provide output audio from the Telos 10 unit. Because of some other equipment in the rack, it took three people to carry it.

Steve made a scheduled presentation on the first day of the show. We were lucky that the presentation room door was about ten yards from our booth. We moved our Anvil case demo system out of the booth and into the conference room for the talk. As we had a phone line in our booth, but the conference room had none, we had the foresight to get a couple of hundred feet of phone cable at Radio Shack the night before.

I was minding the booth during the presentation, so I did not see Steve’s presentation. Neil Glassman, who worked for me at the time, told me Steve started off with a few slides about Slim Whitman. (If you were there, perhaps you can confirm this.) I’m told when Steve got to the actual demonstration of the hybrid’s capabilities, he received a standing ovation.

When the presentation ended (our cue was more applause), we schlepped the rack back to our booth. The rack was like the Pied Piper – we were followed by a line of people leaving the conference room, all wanting their personal demonstration. Standing patiently in the line were corporate radio chief engineers, TV network types wanting to use the Telos 10 with their intercoms and individual station engineers who needed to hear for themselves.

Telos 10For the rest of the show, our booth was packed with customers lining up for a personal demo, and to place their orders for the new system. Everybody wanted one (or more), and they all wanted it right away! Customers visiting the booth wanted to place calls to their stations, and then stick the microphone into the speaker, to prove there was no feedback. Word spread quickly among the attendees about this remarkable new product. We left the show with nearly 25 new orders for the Telos 10.

Over the course of the next year, many large market stations, and most of the talk radio networks purchased multiple units for their talk shows. When we got a call for a brochure, we would send the full manual in a three-ring binder. [Here's a PDF of the manual.]

Did the Telos 10 – the first broadcast audio product to apply digital signal processing technology – cause the surge in call-in programming of the late 1980s? I guess we can’t know for certain, but that was one amazing NAB for a reluctant tinkerer and the guys who encouraged him.

Topics: Broadcast Telephone Systems, Telos Systems

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