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Old 21st Jan 2023, 5:29 pm   #1
robin coleman
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Default Sinclair +2

Is there a cheap and easy way to connect a spectrum + to a modern day television. Which does not ruin the original?

Regards, Robin.
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Old 21st Jan 2023, 7:08 pm   #2
ortek_service
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Default Re: Sinclair +2

It depends on how 'modern' your TV is.
Providing it still has SCART Inputs, then as the Spectrum +2 has an RGB / Composite-Video output, you just need to make-up (or buy a ready-made, assuming there's a few retro computer parts places doing these) lead for this.
And should also be able to have sound via this (on +2A at least)


If the TV still has an Analogue Tuner, then could just use the TV RF Output from the +2. But if TV doesn't have fine-tune, and only fixed channel numbers, then might need to tweak the ferrite core in the modulator inside the +2 a bit.
However, have to be very careful as a steel screwdriver will often break that / affects tuning as you insert it. So need to use a nylon / ceramic adjustment tool, or an appropriate copper blade one.
Also ferrite core may have seized in position / have wax sealing it, so might need to heat the copper blade a bit first, that then conducts heat into ferrite core, freeing it up when gently turning it.
But might find the modulator drifts, so may require future adjustment, and RGB (or even composite) video should also give rather better image quality.

It's also possible that the TV doesn't like the video timing etc.

Another possibility is to use one of those fairly cheap RGB / Composite to VGA / DVI etc. or SCART to HDMI adaptors, depending on what inputs your TV has.

A quick Google, found this good document: https://mts.speccy.cz/doc/128_rgb.pdf (Attached)
on how to wire it all up for various 128 / +2A / +3B versions of the Spectrum, with RGB / CVBS out
Attached Files
File Type: pdf 128_rgb.pdf (276.9 KB, 65 views)

Last edited by ortek_service; 21st Jan 2023 at 7:19 pm.
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Old 21st Jan 2023, 9:24 pm   #3
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Default Re: Sinclair +2

I would also encourage the use of the RGB-out available on the +2 monitor socket as this will give you a picture orders of magnitude better than composite-out, because the Spectrum's composite colour output is not very clean.

Yes, you can still buy ready made Spectrum +2 -> RGB SCART cables or brew your own as per the link Owen dug up in the previous post. Be careful to order or construct the exact one for your Spectrum model.

Obviously, this option needs you to have a TV with a SCART socket which supports RGB-in, or a standard definition CRT video monitor with RGB-in like the Philips CM8833 series.

Edit: Just read the last line 'Modern day television' - are we then talking about something which only has HDMI inputs?

Last edited by SiriusHardware; 21st Jan 2023 at 9:37 pm.
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Old 21st Jan 2023, 10:21 pm   #4
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Default Re: Sinclair +2

The OP mentioned just a + if that is the 48K+ then the best way is just to desolder the resistor from inside the modulator can to the UHF output moving it aside and cut its power lead and link using a capacitor direct from the composite feed.

This is easily reversible and provides a reasonable quality output.

https://spectrumforeveryone.com/tech...the-48k-range/
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Old 21st Jan 2023, 11:35 pm   #5
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Default Re: Sinclair +2

Quote:
Originally Posted by Timbucus View Post
The OP mentioned just a +
>>
>>
I hadn't spotted the OP only said '+' in the text
However, they had said '+2' in the thread title, so I assume that was what they meant, and unlikely to have put a '2' by accident on there.

But there are two versions of the '2', with the original (non '2A') being basically more of a re-cased (+ tape-deck) Spectrum 128, using the same RGB/video-output connector as that. Whereas the '+2A' was basically the +3 (with the later RGB/video + Audio connector) with the FDC part of the PCB literally removed (so had a rather odd shape on the right-side)

Although the article I linked two does cover all four of these versions, that came after the original Spectrum 16K/48K/+ (Which you could access some of the video signals from the edge connector / there was the odd YUV to RGB Interface sold by Ferguson etc for these / they did a TV-Monitor for it. Although I had just wired a screened cable to the modulator input on mine, like many others.).

Last edited by ortek_service; 21st Jan 2023 at 11:43 pm.
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Old 22nd Jan 2023, 9:10 pm   #6
robin coleman
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Default Re: Sinclair +2

Sorry for the confusion. It is indeed the grey +2 128k. They were made in Taiwan at the time and re modded to mod level 5 by myself and a few of Clive's staff. I have seen a cap mod done on the internet as I would like to get it going again for my grandson. I have a SCART plug but no RGB plugs. I presume these are similar to the old 5 pin DIN plugs?
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Old 23rd Jan 2023, 10:37 am   #7
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Default Re: Sinclair +2

It is a DIN plug, 8-pin in this case as shown on Paul Farrow's site here:-

http://www.fruitcake.plus.com/Sincla...CablePlus2.htm

If you were involved in building or modifying these you may know that the 3 x 2N3904 transistors were fitted the wrong way around in many of the mainboards. This caused surprisingly little trouble (I only corrected the error on my own +2A last year) but one of the areas affected is the video-out socket.

There is a common mod for most Spectrums which have a UHF modulator, which is to 'jump' the composite video going into the modulator can across to what was originally the UHF output socket, sometimes directly or via a resistor or capacitor. This will give you composite colour video out which can be fed into the yellow 'AV' socket of any TV which has one, or to the composite-in connections on a SCART input.

Nearly all but the most recent modern TVs I have seen have still had 'analogue' tuning capability so if yours is one like that you may be able to tune it in on the TV in 'analogue TV' mode without modifying the computer at all.

Last edited by SiriusHardware; 23rd Jan 2023 at 10:46 am.
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Old 23rd Jan 2023, 12:46 pm   #8
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Default Re: Sinclair +2

Just looking at that diagram from Paul Farrow's site it appears as though the 8-pin DIN video output may already have composite video (CVBS) available on pin 2, if so, no need to muck about inside the modulator.
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Old 24th Jan 2023, 1:51 am   #9
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Default Re: Sinclair +2

Quote:
Originally Posted by SiriusHardware View Post
It is a DIN plug, 8-pin in this case as shown on Paul Farrow's site here:-

http://www.fruitcake.plus.com/Sincla...CablePlus2.htm

>>.

It seems the document I'd originally linked to / attached, was also from Paul Farrow / his www.fruitcase.plus.com website - as it is marked as such. So may also be available from there (possibly a later version)


Quote:
Originally Posted by SiriusHardware View Post
Just looking at that diagram from Paul Farrow's site it appears as though the 8-pin DIN video output may already have composite video (CVBS) available on pin 2, if so, no need to muck about inside the modulator.
This website is selling ready-made 8-pin Plug video+audio leads: https://www.dataserve-retro.co.uk/co.../en-uk/d8.html (They do sell a few connectors, but don't seem to list this one.)
- To RCA-Phono composite video + audio, for original +2, so could just use with a Standard SCART-Plug-to-Video+audio-Phono-sockets adaptor.
(as well as a SCART version for the +2A - where it seems on the later-version, they strangely decided to deleted Composite video to Pin1 and permanently wired it to +12V that had been an alternative option-link on original +2):

There's probably also some places that do +2 to SCART ones, maybe also using RGB for best-quality (usually at least one TV SCART accepted RGB) and doing the combining with the Bright signal that the later +2A did internally.


Quote:
Originally Posted by SiriusHardware View Post
>>
>>
Nearly all but the most recent modern TVs I have seen have still had 'analogue' tuning capability so if yours is one like that you may be able to tune it in on the TV in 'analogue TV' mode without modifying the computer at all.
I think the main problem might be that may modern PLL-synthesised TV tuners no longer have fine-tuning / AFC, as expect the transmitter's frequency to be very accurate. So you might need to tweak the modulator's frquency to be bang-on one of the channels (rg 36 etc), and hope it doesn't drift a bit over time / temperature.

Last edited by ortek_service; 24th Jan 2023 at 2:03 am.
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Old 6th Feb 2023, 7:37 pm   #10
robin coleman
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Default Re: Sinclair +2

I have now managed to get the display on the television with a bit of ad-hoc. Now I will have to clean the membrane as I get no response from the keys.
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