Vintage Standards Converter

Vintage Television Standards Converter

The converter came from the ITA Burnhope transmitter site
and was used from 1967 until 1984, this converter although not in its original cabinet has been repaired and restored to working condition, there are still some 'store' faults and a few intermittent gremlins to be sorted.

The converter uses Analogue signal processing throughout,
The active part of the 625-line input is chopped into 576 samples and stored on capacitors in a filter network, this is re-sampled at the required 405-line rate, the signal is processed in the output section, has 405-line sync and blanking added to make the composite 405-line video signal.

The converter uses mostly Germanium and some silicon transistors,
in the store section, there are 1,152 OC140 switching transistors, 576 Pot-core inductors 1,152 capacitors, spread over nine circuit boards.

The converter is a very clever design and for the period, was very advanced,
it uses sampling, filtering and some digital counting in the sync converter section. Today sampling a video signal at 11 MHz is easy, back then, with discrete components, analogue processing and storage of sampled video,
presented some very tough challenges, the BBC designs Department produced a workable, (mostly) maintenance free solution to converting 625 to 405-line.

There will be some more information posted on the http://www.domino405.co.uk site at some point.

Category:

Science & Technology

Tags:

• Television
• 405
• line
• vintage
• standards
• converter
• analogue

[albertusj]

I wouldn't have blamed them if they just wanted to point a 405 line camera at a 625 line display. Very complex. It just shows how much value they placed on picture quality.

[stentorp]

First class effort, it's hard to believe it works with so much to go wrong ! Excellent !

[hasanyonetakenthis1]

Fascinating stuff!

[stupidrubbish]

Many thanks for uploading this - it was fascinating to watch, and I'm so glad that one of these convertors has found a good home.