Ideas for a homemade tv set?

KeepItSimpleStupid said:

Is a TV a settop box and a monitor? So, create composite video. You can display that on a VGA monitor with a converter.

I think the tuner would be the hardest part. The tuner of yesteryear was a big rotalry switch that switched in components an dit had a tunable slug for each station for fine tuning. Not frequency synthesis.

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Only for VHF, which ceased in the UK last century, and was only ever used for the 405 (started pre-WWII) channels.

It could be useful.
he is widely know as diodegonewild

I have a bunch of chips like this or similar if you want to go solid state....

Fintek said:

I have a bunch of chips like this or similar if you want to go solid state....

TA8879N datasheet, tv equivalent, Toshiba Semiconductor

TA8879N datasheet, TA8879N tv equivalent, Toshiba Semiconductor, Features and benefits, Stock and price

datasheetspdf.com

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There doesn't seem much point making a TV in the first place, but if you're going to it may as well be an old valve one

I went to my friends yesterday (to pick up a load of stuff he'd built for us, we sub-contract some work to him to save us some work, and to make him some money), he's still repairing TV's, but there's little or no money in it.

Any way - back to the point - when where I used to work closed, he was given pretty well everything out of the buildings (with the exception of new stock of course), including the contents of our 'museum' - which was an attic room full of old electronics and electrical goods, which we considered worth 'saving for prosperity'. We also used to rent them out to TV and Film sets, who were looking for period correct props.

Some of the sets worked, some I had repaired and still worked, some didn't work, some hadn't even been tried.

So while Michael has been on furlough due to Covid 19 he's been repairing a few of our old museum sets - and is currently working on a GEC valve set, about 17 inch, dual standard, very compact and hard to work on - and with the terrible quality GEC double-sided PCB's. He's also recently repaired one of the other sets by rebuilding the tripler - he hadn't got one to fit it, and the ones he managed to 'make fit' had the wrong value focus resistors. So he dug the original one apart, and replaced the rectifiers in it - even sourcing the correct original rectifiers - and then re-potting it.

I suspect this could have been down to the fact we provided him with potting compound for the work we gave him, so he perhaps nicked some of that

What he would like, if anybody has one they don't want?, is a 625 to 405 line converter - so he can actually run his 405 line sets. They seem pretty rare these days, and expensive when you can find them.

Nigel Goodwin said:

If I remember correctly, Sutton Coldfield (Midlands) was on channel 2, and Holmemoss (Yorkshire) was on channel 4 - Alexandra Palace (London) I think was on channel 1?. All were BBC only of course back then.

In our service area we had a mix of Sutton Coldfield and Holmemoss, depending where you lived.

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At the time we were on the fringe of London and the Midlands TV, so you may receive one, your neighbor on the other Ch .
A field tech at the time relayed an amusing incident he had when out on a service call, the wife used to watch a soap of the time and she made a complaint that her set was receiving the TV shows a day late, her neighbor was updating her on events of the show ahead of time,
After a checking the set, the tech realized she was on midlands , the neighbour on London and the show ran a day later on midlands TV!

I tried this once, and it was back in the day when you could still buy the IF transformers, etc. that an old analog TV set used. Never got to square one, just too big a job to start from scratch. Finally found an old Hallicrafters TV in a Goodwill (thrift) store and rebuilt it on inverted baking pans (for chassis). Worked like a champ. Strange pushbutton tuner on that set!

As for what to watch, I don't know about the rest of the world, but here in the US there were very inexpensive (almost free) digital converter boxes sold during the changeover-to-digital period. That would provide program material in old fashioned NTSC from today's broadcasts.

If you are wanting to build from scratch, a complete mechanical TV system is not all that difficult to make, and although the images are very crude, faces are recognizable and you can even record your video on a cassette or .wav file (MP3 throws away too much info). Look into it at: **broken link removed**. Really fun!

electrojim said:

I tried this once, and it was back in the day when you could still buy the IF transformers, etc. that an old analog TV set used. Never got to square one, just too big a job to start from scratch. Finally found an old Hallicrafters TV in a Goodwill (thrift) store and rebuilt it on inverted baking pans (for chassis). Worked like a champ. Strange pushbutton tuner on that set!

As for what to watch, I don't know about the rest of the world, but here in the US there were very inexpensive (almost free) digital converter boxes sold during the changeover-to-digital period. That would provide program material in old fashioned NTSC from today's broadcasts.

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On 'modern' sets it's not an issue, as DTT boxes are still available here, although are pretty uncommon now, so long after DSO.

The issue is the VERY old 405 line VHF B&W sets, where there was never any point having a converter, and would have been FAR too expensive back in those days anyway. Even now, while such converters are still 'just about' available they cost more than many decent large screen LCD sets.

This only affects the UK of course, who (as far as I know?) were the only country to use 405 - similar problem in France, as they (considerably later then the UK with 405) used 819 line B&W.

The USA coming to the party somewhat later than the UK, wisely (at the time) adopted 525 line, and then later added NTSC colour - both poor decisions in hindsight - as other countries skipped over both and went (mostly) for the superior 625 line PAL system. While the UK closed their 405 system and moved to 625 (over a few decades), the USA never upgraded - so were stuck with an inferior old system, and were unable to go widescreen.

Then of course, we all went digital, and the USA at last got widescreen and lost the problems of NTSC.

It's all down to early adopters:

The UK were 'stuck' with 405 as the first adopters - but as it was VHF only, were able to add a second 625 line UHF service to eventually replace it.

Then the USA were stuck with 525 and NTSC for even longer.

I presume many countries came in directly at 625, and avoided any problems until DSO - but they missed the best parts of the party