GEC Dual standard TV identification

[Vakito227]

Hi all, recently aquired this smart looking GEC TV looks to be from around the mid 60s

Does anybody know what model number this is so I can get some service sheets sorted?

Thanks
Peter

[Nuvistor]

I am not good with model numbers but try something like a BT455, photos of the chassis may help someone recognise the circuit you need.

[FERNSEH]

Similar to the Sobell ST196DS-T.

DFWB.

[Focus Diode]

Indeed similar to the ST196. I once had the McMichael equivalent (fully dual standard) MT763DST with a Sobell ST196 rear cover!

They date from circa 1963.

Think this GEC is a BT455(?). Clearly the UHF tuner hasn't been fitted and will probably be found with a single standard IF panel, instantly recognisable by being on a PCB. The dual standard version's panel is hand wired.

Very nice sets but the control panel is a weakness. Interesting that they employ a PY33 HT rectifier too.

Do you plan to restore the set? Would be interesting to hear how you get on.

Brian R

[Restoration73]

Basic model is BT452DS. (T) indicates uhf tuner fitted. I have the Trader sheets for this
and the tuners. Optional extra plug on panel for flywheel sync.
PM if needed.

[Vakito227]

Hi, I may be interested in the UHF tuner if my set doesn't have one fitted but correct me if I'm wrong but isn't that assembly with 2 valves to the left the UHF tuner?

Peter

[Graham G3ZVT]

It certainly is.

[Focus Diode]

It's clearly not the chassis I thought it would be. Looks like an early 2000 series set. Think it was introduced in 1964?

Brian

[FERNSEH]

The valve UHF tuner is of Philips manufacture and the VHF tuner is a product of Radio and Allied Industries. The GEC 2000 and the Sobell 1000 had all the user controls on the front panel.

DFWB.

[FERNSEH]

I'm convinced it's a GEC BT455DS-T. Made for the 1964 model year. Replaced later that year by the model 2000DS-(T).
Note the EH90 FM sound demodulator, works as an AF amplifier on 405 lines.

DFWB.

[steve1010uk]

I also think its a 196, one of my favourite sets i fixed hundreds of them and fitted UHF tuners to quite a few, i seem to remember most faults were 1.2 meg for low height 4.7 meg x2 for low width both fitted on the small sub assembly under LOPT and 5.6k and 18k resistors around EH90 valve going low and burning up.
great pictures and easy to work on, it's successor was the 2000 chassis which used the PFL200 video op valve but was very similar

Steve

[FERNSEH]

"it's successor was the 2000 chassis which used the PFL200 video op valve but was very similar. Steve."

Radio and Allied Industries was always quick of the mark when it came to fitting the latest valves and tubes into their sets. Mullard would announce a new valve type and in no time at all you'll find it in a Sobell TV.

DFWB.

[Vakito227]

Thanks for all the info, can't wait to start working on it once my current project is finished!
Peter

[Focus Diode]

The chassis I was thinking of is the one with the two vertical panels and the PY33 HT rectifier at the bottom centre under the dropper.

The Sobell ST196 must have been one of these as there was space for the vertical thumb wheel controls on the right, as with the McMichael I used to have.

The set here is clearly a later design. Not quite a 2000 series though!



Brian

[steve1010uk]

"The chassis I was thinking of is the one with the two vertical panels and the PY33 HT rectifier at the bottom centre under the dropper."

I think that might be the sobell 195, the one that often seemed to have low brightness due to leaky capacitors

[slidertogrid]

Is it not a GEC 1000 chassis? same chassis as this? https://www.vintage-radio.net/forum/...ad.php?t=38042.

I have an identical set in the spare room but unfortunately the model number label has gone missing from the back cover..

[FERNSEH]

That's right the earlier convertible and dual standard Sobell TVs employed the chassis that had two vertical chassis assemblies. The GEC BT448 is similar except that the early convertible versions employed Mazda valves and CRT, frame output valve is Mazda 30PL14 instead of PCL85.
As Brian states the Mullard PY33 is the HT rectifier, a legacy from earlier R & A circuit designs. GEC BT448DS-T is the dual standard model.
The ST196 and BT455 are much better sets and were brand new clean sheet designs in 1963.

DFWB.

[1100 man]

Hi Peter,
From what I can see in your picture it is the same chassis as my GEC 2000 DST. My thread, with some chassis pictures is here. Have a look and see if yours is the same as mine!

https://www.vintage-radio.net/forum/...d.php?t=137452

The circuit is in the 1964/65 R&TV book but is not great quality and really needs to be scanned to be readable. Unfortunately, I don't have one!
Good chassis and works very well.

Cheers
Nick

[FERNSEH]

The GEC 2000 and Sobell 1000 are developments of the BT455 and ST196. The later sets were sold as fully dual standard models with UHF tuners and never as 405 only convertible receivers as the earlier sets were.
The 1000 and 2000 sets have the then newly introduced PFL200 double-pentode to replace the PCL84 video amplifier. Doesn't the 2000 use the PCF802 as the line oscillator valve?
Easy changeover to UHF625 by selecting a position on the VHF tuner.
Much of the circuit design is similar in all these receivers.
BT455 and ST196 have a separate 405/625 switch on the cabinet right side.

DFWB.

[1100 man]

Looking at the picture, I've been trying to work out of it's got a PFL200 or a PCL84 fitted. It looks more like a PCL84 to me. So with a manually operated system switch that would make it a BT454, 455 or 456 I would guess!

The 2000 does indeed use a PCF802 as line osc.

In fact here is a picture of the very set in this thread! BT456. Look at the zip files in post 6!

https://www.vintage-radio.net/forum/...ad.php?t=38042

Nick