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Old 12th Jul 2019, 5:55 am   #20
Radio Wrangler
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Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 12,584
Default Re: Dormer & Wadsworth (D&W)

Until you mentioned them here, I hadn't known they existed. I'd seen Larsholt ubits in some magazine projects, I knew about the Mullard modules, and were there ones by Gorling (sp?) in some German/Austrian radios?

In the 1990s, analogue TV was still dominant and cable system operators wanted to add a quality monitoring system to look at the VITS (Vision inserted test signal) that is added in one of the unused lines. From this you can get bandwidth, diff gain and diff phase, etc.

They wanted a test box to demodulate and test each channel in turn, and if a fault persisted long enough to not be a glitch, to fire up a modem and 'phone home' with a report to some central monitoring facility.

The reason for all this was the advertisers. Advertisers had long argued that not all parts of a distribution network got good enough quality all the time, and used this supported by ad-hoc monitoring to argue down the price of running their ads.

There must have been sufficient money dependent on this for getting the cable firms interested in thorough network monitoring. Quality parameters, not just signal presence.

An R&D project at HP repackaged video digitiser and CPU cards that existed in spectrum analysers with a TV tuner/demod module for the TV standard of the target market.

We found a series of tunerr/demods from Philips with variants for each of the standards we had to cover. Then our problems began. Philips provided samples freely, but thereafter Philips did not want to deal with us. We didn't want the sort of quantities a TV setmaker used. "Go through a distributor!" we were told. The distributors were no better. They didn't handle this product range because setmakers dealt directly with Philips. The distributors would be delighted to deal with us, but as Philips would only sell to them in units of a pallet-load, the distributors imposed the same requirement on us. They would have no other customers for them.

Anyway, analogue TV distribution was drawing to a close and interest was fading. Add in the Philips problem and although the project was just on the threshold of full production, it was quietly withdrawn from the catalogue. If this sounds like a lame product, it was worse than that. Truly accursed would be accurate. A safety recall hit the units which had gone out. All the units were got back, except one which no-one could trace.

I got dropped in to manage the project part way through. I have an enduring urge to run at the mention of 'tuner', and a tendency to avoid Philips parts of any type.

David
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