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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 23rd Nov 2021, 9:02 am   #41
beery
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Default Re: Another TV22

Hi Bren,
I'm glad you got there in the end. Broken leads on coils can be hard to spot.

I'm sure I have spare aerial/RF cores for a TV22, but I won't be able to get to them until Christmas.

Cheers
Andy
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Old 23rd Nov 2021, 1:11 pm   #42
EF80TVVALVE
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Default Re: Another TV22

Yes, it's just one of those things, we've all been there! That's great to hear Andy, keep me in mind for one but I'll scour elsewhere in the meantime, as you can imagine my patience in getting to the picture stage is now wearing thin!

I did manage to get a test tone through the speaker at one stage before the frame collapse had been sorted but all is silent now, I' m going to focus on the RF deck tonight and see if I can solve its issues. With luck the damaged core may not matter too much with the set being directly fed from the aurora.
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Old 23rd Nov 2021, 9:15 pm   #43
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Default Re: Another TV22

Well this evening we have Test Card C of sorts, a very weak signal no doubt partly the fault of the missing core. I have removed the BIII converter which lead me to these results, presumably the BI/III switching was very dirty. I will have a think of what to do with the converter, I may sort it out at a later date and refit.

In the mean time I'm going to test the valves on the RF deck, they all look very well used. I know you can never judge just by looks but some of them do look like they've had a very hard life, it makes you wonder how long some of these sets were in use for. Judging by some of the old repairs prior to restoration this one looks like it was still being used into the 1970s.
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Old 23rd Nov 2021, 9:55 pm   #44
murphyv310
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Default Re: Another TV22

Hi
At least you have somthing on screen and it can only get better.
The oldest set I saw actually working in a home was a Pye V4 around 1970/71. It was used as a spare set in a bedroom and was very good.
Another V4 was rescued from British Relays bin and was done up to test the "Vid boxes" which I converted to 625 lines. That was in 1971 as well.
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Old 24th Nov 2021, 2:39 pm   #45
EF80TVVALVE
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Default Re: Another TV22

Yes I'm sure with some further attention to the RF deck it will be good. Interestingly I do have an RF deck for a TV12, I'm tempted to see how compatible it is with the TV22. Initial thoughts were that it wouldn't be at all, but then I recall the TV12AM which (if memory serves me right) utilised the same main deck as the TV22, however I don't know if there are still differences between the main deck on the 12AM and the 22. It would certainly be interesting to see whilst I source some cores and make further repairs to the RF deck.
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Old 24th Nov 2021, 6:02 pm   #46
Lloyd 1985
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Default Re: Another TV22

I have tried a TV22 RF chassis in a TV12 before and it worked! The TV12’s RF chassis was having a few issues which turned out to be an OC coil, so I had the TV12 running like that for a while! Mine was the version with EF91’s and didn’t have the extra tag strip on the back that some others have.

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Old 24th Nov 2021, 6:13 pm   #47
EF80TVVALVE
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Default Re: Another TV22

Yes that's my thinking Lloyd, mine has EF80s with the tag board so I'd need to replace that bit of circuitry within the set which is only a few resistors and cap if I remember correctly.

Cheers
Bren
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Old 24th Nov 2021, 11:39 pm   #48
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Default Re: Another TV22

Well tonight's workings have been checking the compatability of the TV12 RF chassis, it required nothing more than a capacitor and a few resistors fitting to the main deck, as well as some alterations to the capacitor feeding the ECL80 from the RF deck. I have had a look over the TV12 RF chassis and it is in very sound, untouched condition. The EF50 valve holders look good bar one which may still work okay. There are two broken tags on one of the B8A sockets (UL41) so one is on order, once this has been replaced we'll see what sort of life we get from it.

Unlike the TV22 RF deck, this one has been left untouched and never fiddled around with. I fear that the TV22 deck is going to take a fair amount of work to get it in good order, so the use of this TV12 deck will hopefully give me a good set for now whilst I can make repairs to the original deck as and when time and parts allow.
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Old 25th Nov 2021, 9:55 am   #49
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Default Re: Another TV22

Hi.
The TV22 RF/IF deck is relatively simple, well laid out with easy access so personally I'd persevere with it. Working with it and repairing the deck is a very good learning curve and it will help your understanding of RF circuitry. With a good signal generator, a decent scope you'll be able to tie down the issues with little trouble.
The chewed core should be able to be extracted reasonably easy and I'm sure If you put a wanted on the forum someone would be able to help.
Using the TV12 deck will add in another bag of worms with fussy valves and perhaps dodgy bases.
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Old 25th Nov 2021, 10:17 am   #50
EF80TVVALVE
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Default Re: Another TV22

Hi Trevor,

I'm certainly not going to give up on the EF80 RF deck, the idea of using the TV12 chassis is just to have the set working in the mean time. The TV12 RF deck is in much better shape so it should work with very little attention, should it prove to be full of faults then I shall go no further and focus solely on the EF80 chassis.

I'm sure with care and attention it can be repaired, I'm suspecting one of the coils may be faulty which may explain why they had been messed around with. Tapping the tuning coil causes signal to come and go as well as tapping some of the EF80s, the first task is to clean all of the sockets more thoroughly and check the coils and go from there.
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Old 25th Nov 2021, 5:06 pm   #51
murphyv310
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Default Re: Another TV22

Hi.
I've just repaired a TV22 deck today. It was multifaulted with at least half a dozen components faulty outwith the usual decouplers.
This one had four resistors seriously off value, a 680ohm G2 feed to the 1st vision IF was low down to less than 300 ohms, the 150 and 33 ohm cathode resistors on the RF amp way low, the 0.0047uf mica decoupler was reading 10k and intermittently going open circuit, the 39k on the oscillator was over double its value. Although it worked the issue was intermittent fluctuating gain and crackling. A couple of minutes with the scope revealed where the problem lay, initially I thought it was dirty valve bases.
Now running spot on (early EF91 type)
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