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Forum 135

CTV 1982 Baird 8233 TX10 Teletext

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Colour Television

Last Post by WayneD 1 week ago

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Jayceebee

(@jayceebee)

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With tapes played back on the same machine it was originally recorded on gives the best chance of playing back some fairly legible text. I’ve seen news pages with the date on the header row, headline and enough uncorrupted info to able to work out the year. Funny that later decoders weren’t as good as the VM6101 and equivalents with the SAA5xxx chipset. Never tried but I wonder how SVHS or DVHS would have fared?

John.

Posted : 09/09/2024 8:44 am

WayneD

(@wayned)

Posts: 895

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Topic starter

@jayceebee this was recorded on my parents' Mitsubishi VCR back in the early 90s, it's long gone!

SVHS definitely recorded the teletext signal at a high enough resolution for it to be decoded. However Jason Robertson of The Teletext Archeologist has a way of recovering teletext from standard VHS and Betamax tapes.

Posted : 09/09/2024 9:07 am

WayneD

(@wayned)

Posts: 895

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Topic starter

@jayceebee now I have VBIT2 Teefax up and running I thought I'd try it using the Raspberry Pi composite video feed directly into the JVC HR-7350 and...

It works! I might try this with a newer VHS HQ machine or the Betamax, along with a 90s TV with composite video input.

Either way, I'm particularly impressed with the teletext of this Baird.

Posted : 12/09/2024 12:28 pm

WayneD

(@wayned)

Posts: 895

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Oh dear, the sweep tuner decided to break over the weekend of Teletext 50 at Cambridge Centre for Computing History. Which was a real shame as quite a few people came up to me and told me they rented one just like it back in the day!

It did work for the first few hours.and it looked bloody good!

Considering all I've done is remove the battery, thoroughly clean the tuner board and repair the tracks it's done pretty well to get this far!

Here's a thing which probably would have kept it going over the weekend, if you lift one leg of R663 and solder a wire to where it was going (pin 5 on the teletext board connector) along with a suitable ground and hook up a Raspberry Pi running VBIT2 Teefax etc you can run teletext directly without having to go through the RF and IF stages:

This also has the advantage that you can run whatever video you like in the background and teletext will still work. Even snow!

I'd imagine this modification works with all Ferguson TX10s and any other TV that uses the same Philips Mullard teletext decoder board, it would just be a case of lifting one leg of the resistor supplying the video signal to the teletext board. It's easily reversible too.

Posted : 26/09/2024 7:54 am

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