Teletext?

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blackwitch
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Teletext?

Post by blackwitch »

Hi.

I've been flicking through some pages here. It seems some people are able to use the Teletext adapters. But I thought it had all been switched off?

Can someone explain if its still possible to use the adapter? If so, what content can be found?

Many thanks
guesser
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Re: Teletext?

Post by guesser »

It was phased out in the UK with the digital switchover, but is still going strong on the continent.

A teletext signal can be generated (with no additional hardware) using a Raspberry Pi, which can then be fed into the Teletext adaptors via a standalone UHF modulator or VCR.

https://github.com/peterkvt80/vbit2/wiki
Various teletext things including a web based teletext editor which can export as mode 7 screens.
Join the Teletext Discord for teletext chat.
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Richard Russell
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Re: Teletext?

Post by Richard Russell »

blackwitch wrote:
Fri Jan 08, 2021 8:11 pm
Can someone explain if its still possible to use the adapter?
I use my little Test Card Generator (sadly no longer available) as a source of teletext.
I am suffering from 'cognitive decline' and depression. If you have a comment about the style or tone of this message please report it to the moderators by clicking the exclamation mark icon, rather than complaining on the public forum.
blackwitch
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Re: Teletext?

Post by blackwitch »

Thanks, guys.

How could I still utilise a BBC cheesewedge Teletext adapter and use it on the beeb? Is that possible?
guesser
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Re: Teletext?

Post by guesser »

blackwitch wrote:
Fri Jan 08, 2021 9:42 pm
Thanks, guys.

How could I still utilise a BBC cheesewedge Teletext adapter and use it on the beeb? Is that possible?
Yep, install vbit2 on a raspberry pi and connect its composite output to the input of a VCR or UHF modulator.
Connect the RF output of the modulator to the antenna input of the cheese wedge, and follow the tuning instructions in the manual. I'd recommend using the ATS ROM.

Image

There's also a way to bypass the modulator and tuner, and just feed the composite signal directly into the adaptor's circuit board. The details have been posted on this forum before somewhere.
Various teletext things including a web based teletext editor which can export as mode 7 screens.
Join the Teletext Discord for teletext chat.
blackwitch
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Re: Teletext?

Post by blackwitch »

Oh cool.

Thanks for that.

Would I be able to view teefax on my BBC monitor rather than using a VCR and a TV?
guesser
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Re: Teletext?

Post by guesser »

blackwitch wrote:
Sun Jan 10, 2021 2:20 am
Would I be able to view teefax on my BBC monitor rather than using a VCR and a TV?
Yes the display on the beeb is whatever you normally use. The VCR (or standalone modulator) is to take the place of the TV transmitter, and get the video signal containing the teletext signal from the pi into the teletext receiver since it is expecting to be connected to an antenna with signals coming over the air which of course are long gone :)

Alternatively you can feed composite into the adaptor directly at a test jumper, but it looks like it requires some amplification/buffering first.
cmjones01 wrote:
Tue Nov 21, 2017 1:51 pm
There's a handy link, LK3, which allows you to disconnect the video from the TDA2541, so I've used that to inject composite video from the RPi via a little amplifier to bring it up to the 2V pk-pk that the SAA5030 wants.
That's not something I've tried myself as I have plenty of ways to modulate an RF signal.
Various teletext things including a web based teletext editor which can export as mode 7 screens.
Join the Teletext Discord for teletext chat.
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