RF output

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Village Idiot
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RF output

Post by Village Idiot »

Hi there.

I don't know if you get many tiresome posts from new users like this on, apologies if you do.

Prompted by my son's interest in retro computers and consoles I have dug out my old QL. We are also buying an Atari VCS so we are all well down Memory Lane here ;)

Anyway, blew off the most amazing amount of dust, plugged said QL into an <old> lcd TV which has a good manual analogue tuning facility, tuned to ch36 and....

....got a bunch of black and white wavy lines. You can actually see merest hints of text in it, but it is rolling and totally unreadable. There is a manual fine tuning on the TV in 1MHz intervals that doesn't help.

Now, I have evidence in effect that the PSU is working and the motherboard is doing something, as unplugging the PSU or hitting reset takes you from static to these wavy lines. But I can't plan my next step and here is where I need help. I can buy an RGB to SCART lead for a tenner or so, if the most likely problem is faulty RF. Or if the problem is more likely to be that this particular TV isn't able to display a possibly weak RF signal then I have sourced an old CRT TV to buy also for a tenner or so (unfortunately I don't own one, nor know someone who does).

I was just wondering if this fault has been seen on the forum before, or alternatively if anyone would like to make a best guess as to what is going on, to help me tune in, pardon the pun, to what my next step should be.

Many thanks if anyone can offer help.

Cheers

VI


Martin_Head
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Re: RF output

Post by Martin_Head »

You wouldn't happen to have an old video recorder about? You could test the TV by tuning the TV into the output of the Video, then plug the QL into the RF in of the of the Video, and then try to to tune the Video in to the QL, using the Video recorder as a buffer.

You would have to watch out for the Video and the QL both using channel 36, so you might have to alter the RF output channel on the Video first.

Also if you QL has not been used for so long, it's a good bet that the keyboard membrane has failed.


Village Idiot
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Re: RF output

Post by Village Idiot »

Thank you Martin, I don't have a VCR myself, but might be able to borrow one actually.

The Atari arrived this morning, so tuning that into this same telly might be interesting/informative.

Cheers

VI


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NormanDunbar
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Re: RF output

Post by NormanDunbar »

If it's been gathering dust for millions of years, then the electrolytic capacitors are probably shot. They live longer if used regularly. There might be other problems of age too. But I'm not an electronic expert.

Cheers,
Norm.


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Village Idiot
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Re: RF output

Post by Village Idiot »

Thanks guys.

Well, it was the TV. On a borrowed CRT I now have a fully readable and stable if a little fuzzy, "(C) 1983 Sinclair Research" and a choice of F1 or F2.

As someone has predicted I can't get any further indicating keyboard membrane. No keys at all do anything right now so I suppose I don't know if just F1 and F2 have gone or others as well.

Is there any keyboard testing I can do if I can't get past this first screen?

Cheers

VI


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vanpeebles
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Re: RF output

Post by vanpeebles »

Sounds like new membrane time :) What games have you got lined up for the Atari?


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1024MAK
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Re: RF output

Post by 1024MAK »

Village Idiot wrote:Is there any keyboard testing I can do if I can't get past this first screen?
No :(

The (standard) QL will just sit waiting for keyboard input to select monitor or TV mode. In the (highly) likely case that the membrane has a fracture crack, it will need to be renewed.

However, if there are no digital glitches on this screen, nearly all the important circuitry is working :D

So time for you to go and browse Sell My Retro for a new membrane ;)

If you do want to get past the first selection screen, you can use a piece of wire to simulate F1 or F2.

Also note that the monitor mode picture is too wide for most displays (the QL produces a picture on all video outputs regardless of whether F1 or F2 is used, the difference is in the area of the screen that is used). For the best quality picture, use a RGB SCART lead.

Mark


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Village Idiot
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Re: RF output

Post by Village Idiot »

vanpeebles wrote:Sounds like new membrane time :) What games have you got lined up for the Atari?
A few classics plus one called Dragonfire that I played a lot as a kid. I don't know if my son is ready for the 'gap' between the Atari and what he is used to now even on his tablet. I guess you could put the whole Atari circuitry on a grain of rice now, apart from the interface to the outside world.

VI


Village Idiot
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Re: RF output

Post by Village Idiot »

1024MAK wrote:
Village Idiot wrote:Is there any keyboard testing I can do if I can't get past this first screen?
No :(

The (standard) QL will just sit waiting for keyboard input to select monitor or TV mode. In the (highly) likely case that the membrane has a fracture crack, it will need to be renewed.

However, if there are no digital glitches on this screen, nearly all the important circuitry is working :D

So time for you to go and browse Sell My Retro for a new membrane ;)

If you do want to get past the first selection screen, you can use a piece of wire to simulate F1 or F2.

Also note that the monitor mode picture is too wide for most displays (the QL produces a picture on all video outputs regardless of whether F1 or F2 is used, the difference is in the area of the screen that is used). For the best quality picture, use a RGB SCART lead.

Mark
Thanks Mark, yes I guess I will be investing in a cable and membrane shortly, now it seems likely not to be wasted money. Cheers, VI


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