A tale of two tellys

[mark pirate]

These two sets came my way via a garage clearance, the first is a rather tatty GEC BT1252 405 line set from 1955, this seems complete apart from the bottom panel and the tuner knob, I already have one of these in my collection, so if nothing else it could be a good source of spares.

The second is a Sobell 20" 625 line only set, probably early 70's?
This is in reasonable condition, but a few chips out of the veneer.
does anyone have any info on this set, as I am not familiar with the chassis, some service info would be great.

I will introduce them to the mains a bit later to see if they are worth restoring.

Mark

[steve1010uk]

Those Sobells were quite good sets although the double sided print could be a bit of a nightmare to work on

I remember a common fault was the 2x 4.7 megohm resistors going high causing lack of width and a resistor in the height control circuit i think possibly 1.2 meg ohm causing lack of height ,

Chop out the mains filter cap, plug it in and stand well back!

[hamid_1]

The Sobell single-standard TV looks like a G.E.C. "Series One" chassis, possibly Sobell model 1047 = equivalent GEC model 2047. I think they were sometimes called "Fineline", perhaps a reference to the new, higher-definition 625 standard.

A near identical one was discused here: https://www.vintage-radio.net/forum/...ad.php?t=56916

Quite a rare find nowadays. I saw someone at the NVCF this year selling a similar GEC branded one, which was working remarkably well. Before that, I hadn't seen one since the mid 1980s. Can't be many about now. Definitely worth saving!

These and other GEC televisions of that era use double-sided print on their circuit boards. They're not the easiest sets to repair - the tracks peel off the board readily. If you have to change any components, it's simpler to cut out the old component and solder the new one onto the leads from the old one. It doesn't look as neat, but it works.

Good luck!

[mark pirate]

Power has now been applied to both sets, and the results are as follows.

The GEC needed the old cloth & rubber mains lead replaced, as it had gone hard and the insulation crumbled on touch, luckily the set itself uses PVC cable, which is fine.
Both fuses had been replaced with 5 amp items, but they were intact, so were left in place as my variac is fused at 2 amp.

Despite the state of this set, it looked sound enough to power up, I have noticed that the barreter had been replaced with a dropper, which looks as ancient as the rest of the set, and appears to be done properly.

The set was run up on my variac, and came to life as the volts increased, the sound came up followed by the familiar 405 whistle, then first light on the screen showed frame collapse, this might have been the reason the set was taken out of service all those years ago, and may explain why there was no screws in the back

The Sobell appears never to have had the back off, there is no sign of any repairs at all, it is truly filthy inside.
By accident the variac was on full mains when I powered it up, but it did not complain, the sound came up ok, but the line stage was dead, on further investigation I noticed there was no heater in the boost diode, with years of filth dusted off the reason was the valve had cracked and gone to air.

It looks like a PY88, (can anyone confirm?) but I don't have one to try.

Thanks for the info on the Sobell, I will follow the advice about the double sided print, as I know from years ago that this can be a real pain.
Any idea what year the Sobell is from?

Both sets show promise, so will join the queue for the workshop.

Mark

[HamishBoxer]

Certainly looks like a PY88

[mark pirate]

Yes, I just looked at the GEC thread, so the question is did it just die, or was it killed off by the line stage?

This set is a bit too modern for my taste, It is really one of the last valve B&W sets, but will be a good winter project.

I wonder if it was purchased to replace the GEC which must have been around 15 years old at the time.

Mark

[Colourstar]

Originally Posted by mark pirate

Any idea what year the Sobell is from?

I should think 1971/2 would be about right for those. There were some more interesting cabinet variations, including some in a white case and some with the controls arranged along with top on a strip of brushed aluminium with the 'Fineline' script. Very smart, but it seems none have survived!

Like Hamid, apart from the one at the NVCF, I've not seen one since about 1985.

Nice sets though!

Steve

[steve1010uk]

It,s a PY88 but you could try a PY81 or PY801 either will do as a temporary substitute,
check for shorts from the PY top cap to chassis as there may be a short circuit line tuning capacitor etc

[mark pirate]

Thanks Steve, I thought early 70's by the style of the set, only seven valves in the set, the rest of the work is done with those three legged things

I did try a PY81/801 but just got a few blue sparks in the valve, I think I need the correct valve before going any further, I just hope the LOPT is ok.
I will check the caps around the line stage before fitting a new PY88.
If anyone has got any service info for this set, please let me know.

Mark

[ntscuser]

Is there any indication of where the GEC was made? I am hoping it was in their Spon Street, Coventry factory before they moved production to Wales.

[MALC SCOTT]

Hi Mark, plenty of nos PY88 valves here

[mark pirate]

Is there any indication of where the GEC was made?

There is no info inside the set apart from a test label, having said that, there may be more info when I have given it a good clean inside!

Thanks for the offer Malc, I have one on it's way to me, but it is untested, so I will let you know if I need one.

Mark

[Welsh Anorak]

Hi there
Can't say I remember any LOPT failures in the Sobell which is encouraging - check the boost capacitor as a short circuit one will overheat the PY88 which might crack and go down to air.
If you need to remove components heat the TOP of the board and use a fine pair of pliers to pull the component up and out - clean the hole and off you go.
It's not the neatest looking chassis but will give a pretty good picture as long as the CRT's OK. I might be wrong but I think this was the very last 'Sobell' badged set so is certainly of interest.
The smaller GEC versions with the controls on the top used to suffer from the speaker, also top mounted, crashing down into the works as the fixings decomposed from the heat! Not the cleverest idea...
Good luck
Glyn

[mark pirate]

check the boost capacitor as a short circuit one will overheat the PY88 which might crack and go down to air.

Hi Glyn, that might have what put the set out of action many years ago, the original PY88 could well have cracked due to overheating.

I will be replacing the boost cap before fitting another valve, I really need to find some service info on it soon.

As for the CRT, it is a Mazda gold star, so I think I will bung it on the B&K and see what the emission is like, the amount of crud round the tube and line stage shows this set to have had a fair amount of use.

Interesting that this set could have been Sobell's last, I guess these are a relatively rare set now, it is not one I remember working on years ago, they were all Thorn 1500's

Mark

[Welsh Anorak]

Hi
You're right - Thorn 1500s seemed to be the most popular hybrid large-screen mono set. Everyone liked them, although the pictures weren't the best.
The other manufacturers put out their token sets which were, on the whole, pretty good. Philips 300, Decca 2X20 (excellent), Bush A774 (er, not so excellent), ITT VC200, GEC Series 1 and 2 and Pye 179 all spring to mind.
LLJ did an article about the GEC sets, ISTR.
Hope the tube's good
Glyn

[mark pirate]

Good news on the Sobell, I checked the boost cap and a few others in the line stage, all seemed well, so in with a NOS PY88 and powered it up, the resulting picture is quite a good result for first light, now I know it will be a worthwhile restoration, it will be tackled later this year.

Mark