General Electric Company Television - UK Vintage Radio Repair and Restoration Discussion Forum

OliverWestby · 9th Feb 2006, 6:45 pm

I have recently bought a GEC model b.t.321 valve television, however, I have been unable to find any information what so ever on the internet about this.
Does anyone have any information about this set, and if possible, a schematic and a list of the capacitors that need replacing.

Thanks
Oliver

Heatercathodeshort · 9th Feb 2006, 9:13 pm

Hello Oliver,
The GEC BT321 is a 17" model released in 1960. It is fitted with an i.f. 'plate' with an extra stage for use in weak reception areas. It is very similar to the BT302 series and was one of the last produced in the old Coventry factory. Future GEC sets were Sobell/McMichael designs built at Slough. They are a very good set and reliable in operation. I repaired many of these sets in the 60's and into the 70's. Weak points are the CRT. This bears the GEC label but originated from the Maxda stable. It will probably be low emission but capable of a reasonable picture. It can be replaced by the Mullard AW43-88 or 89. Regards. JOHN.

Duke_Nukem · 9th Feb 2006, 11:00 pm

It is covered by the trader service sheet #1475 and as John has said was released in 1960 (June). The 321 is a fringe model.

TTFN,
Jon

OliverWestby · 10th Feb 2006, 12:29 am

Cheers guys,
I will replace the capacitors and turn it on. Is there anything else that I should know before turning it on.
Does anyone know the value of this set in unrestored resonable condition (one scratch on top) and in perfect working condition?

Also, where do I find this trader service sheet?

Thanks
Oliver

dazzlevision · 10th Feb 2006, 9:35 am

Hello,

Over the last year or so, there have been several GEC sets of the type you have on Ebay. I bought the 17" BT322 (with VHF/FM radio), for £30 in 2004 and another, the 19" BT342 (again, with VHF radio) for £5 last year. Some people think these bow fronted GEC sets are hideously ugly - others do not. They are certainly not in the "highly collectable" group, unlike the bakelite Bush TVs.

So, more recent Ebay auctions for this type of set have not sold for as much - more like £10-15.

I scrapped my BT322 for spares to use with the BT342 (the cabinet was quite rough). After complete electrical restoration, my BT342 has developed a Line Output Transformer (LOPT) problem - the picture width narrows after 10 minutes or so and untlimately, the picture disappears (EHT rectifier heater voltage too low). This is an all too common problem with "pitch" covered LOPTs of this age and which have lain unused for at least two decades - so beware!

I replaced ALL the wax and black "Hunts" type capacitors - they were all faulty. Don't scrimp on this, or you may cause other components to fail as a result, especially anode to grid 1 coupling capacitors.

I also had: a low emission 6F23 vision IF valve, a leaky vision detector Germanium crystal diode which caused picture highlight crushing as the contrast control was advanced, several out of tolerance carbon resistors and a worn out HT smoothing electrolytic can. If your set still has the original metal rectifier for HT, it will almost certainly be u/s - high forward resistance, causing low HT - replace with a silicon diode and 20 Ohm / 10 Watt series surge limiter. The original GEC (Mazda!) CRT had already been replaced with a nice Mullard type - phew!

I too like these sets - the last true GECs. It has always puzzled me why GEC never made any of these sets with "flywheel" line synce - even though they did make a "fringe" version, such as the one you have - with an extra vision IF stage, to up the sensitivity. With weak signals, sets without flywheel sync tended to suffer from "line tearing" - ragged verticals.

Regards,

Dazzlevision

Dave Moll · 10th Feb 2006, 9:54 am

Quote:

Originally Posted by OliverWestby

Also, where do I find this trader service sheet?

Thanks
Oliver

I believe that the CDs of "Trader" sheets are sent out free when one joins the BVWS, assuming that they are still in stock.

Heatercathodeshort · 10th Feb 2006, 8:28 pm

Hello Dazz,
Your comments on the lack of flywheel sync on the GEC BT321 is an interesting point. I cannot think off the top of my head of a single genuine GEC set that used flywheel sync and gated AGC in their fringe models. There may be a couple but I dont think I have ever seen one. They always relied on the extra gain provided by the aditional I.F. stage. Thinking about it, the problems encountered with the early flywheel sync sets probably caused more problems than they cured. This was mainly due to faulty capacitors and metal diodes rather than circuit design. GEC may not have been so backward appearing as they seemed. Customers certainly did like the 'Kidney shaped' design but a few as you say Hated it!
Hello Oliver! The value of the set is very low as suggested. I don't think it will be a basis for an inflation proof pension. If your interested in the set from an enthusiasts point of view it will be great to get it working. I have the BT302 in my collection but as Dazz says it will be very much a labour of love getting it working as most of these vintage receivers usually are!
Regards. JOHN.

Duke_Nukem · 10th Feb 2006, 9:10 pm

As well as the puzzling lack of flywheel sync, it also puzzles me how on earth it could have been worthwhile them creating 6 different versions, each populated with different combinations of fitted channel coils - one with "all" channels (1..5,8..11) ? The versions are indentified by a colour code on the aerial panel, so before cracking on with the set it might pay to make sure you have an appropriate modulator. I dunno, what a cheapskate company.

Anyhow I've unearthed the manual and might be able to scan it if still required.

TTFN,
Jon

PS The trader sheet gives the incorrect date, a letter from GEC in late June said that the consolette versions BT320/1 would be released"later in the year".

OliverWestby · 10th Feb 2006, 11:35 pm

Hey,
Thanks for all your replies. My friend and I are into valve radios/televisions, and we are more keen in the novelty of making them work than selling them. My friend got a Bush TV43 for £3!
If you could scan the service sheet for me that would be great. I would become a member of bvws, but as a student I don't have the money to do this.

Oliver

Duke_Nukem · 11th Feb 2006, 6:21 pm

You can download the manual here :-

http://www.thevalvepage.com/tvmanu/gec/gec.htm

It's all the way down the bottom of the page.

TTFN,
Jon

9th Feb 2006, 9:13 pm	#2
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: General Electric Company Television Hello Oliver, The GEC BT321 is a 17" model released in 1960. It is fitted with an i.f. 'plate' with an extra stage for use in weak reception areas. It is very similar to the BT302 series and was one of the last produced in the old Coventry factory. Future GEC sets were Sobell/McMichael designs built at Slough. They are a very good set and reliable in operation. I repaired many of these sets in the 60's and into the 70's. Weak points are the CRT. This bears the GEC label but originated from the Maxda stable. It will probably be low emission but capable of a reasonable picture. It can be replaced by the Mullard AW43-88 or 89. Regards. JOHN.

9th Feb 2006, 11:00 pm	#3
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: General Electric Company Television It is covered by the trader service sheet #1475 and as John has said was released in 1960 (June). The 321 is a fringe model. TTFN, Jon

10th Feb 2006, 12:29 am	#4
OliverWestby Retired Dormant Member Join Date: Sep 2005 Location: England Posts: 16	Re: General Electric Company Television Cheers guys, I will replace the capacitors and turn it on. Is there anything else that I should know before turning it on. Does anyone know the value of this set in unrestored resonable condition (one scratch on top) and in perfect working condition? Also, where do I find this trader service sheet? Thanks Oliver

10th Feb 2006, 9:35 am	#5
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,621	Re: General Electric Company Television Hello, Over the last year or so, there have been several GEC sets of the type you have on Ebay. I bought the 17" BT322 (with VHF/FM radio), for £30 in 2004 and another, the 19" BT342 (again, with VHF radio) for £5 last year. Some people think these bow fronted GEC sets are hideously ugly - others do not. They are certainly not in the "highly collectable" group, unlike the bakelite Bush TVs. So, more recent Ebay auctions for this type of set have not sold for as much - more like £10-15. I scrapped my BT322 for spares to use with the BT342 (the cabinet was quite rough). After complete electrical restoration, my BT342 has developed a Line Output Transformer (LOPT) problem - the picture width narrows after 10 minutes or so and untlimately, the picture disappears (EHT rectifier heater voltage too low). This is an all too common problem with "pitch" covered LOPTs of this age and which have lain unused for at least two decades - so beware! I replaced ALL the wax and black "Hunts" type capacitors - they were all faulty. Don't scrimp on this, or you may cause other components to fail as a result, especially anode to grid 1 coupling capacitors. I also had: a low emission 6F23 vision IF valve, a leaky vision detector Germanium crystal diode which caused picture highlight crushing as the contrast control was advanced, several out of tolerance carbon resistors and a worn out HT smoothing electrolytic can. If your set still has the original metal rectifier for HT, it will almost certainly be u/s - high forward resistance, causing low HT - replace with a silicon diode and 20 Ohm / 10 Watt series surge limiter. The original GEC (Mazda!) CRT had already been replaced with a nice Mullard type - phew! I too like these sets - the last true GECs. It has always puzzled me why GEC never made any of these sets with "flywheel" line synce - even though they did make a "fringe" version, such as the one you have - with an extra vision IF stage, to up the sensitivity. With weak signals, sets without flywheel sync tended to suffer from "line tearing" - ragged verticals. Regards, Dazzlevision

10th Feb 2006, 8:28 pm	#7
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: General Electric Company Television Hello Dazz, Your comments on the lack of flywheel sync on the GEC BT321 is an interesting point. I cannot think off the top of my head of a single genuine GEC set that used flywheel sync and gated AGC in their fringe models. There may be a couple but I dont think I have ever seen one. They always relied on the extra gain provided by the aditional I.F. stage. Thinking about it, the problems encountered with the early flywheel sync sets probably caused more problems than they cured. This was mainly due to faulty capacitors and metal diodes rather than circuit design. GEC may not have been so backward appearing as they seemed. Customers certainly did like the 'Kidney shaped' design but a few as you say Hated it! Hello Oliver! The value of the set is very low as suggested. I don't think it will be a basis for an inflation proof pension. If your interested in the set from an enthusiasts point of view it will be great to get it working. I have the BT302 in my collection but as Dazz says it will be very much a labour of love getting it working as most of these vintage receivers usually are! Regards. JOHN.

9th Feb 2006, 6:45 pm	#1
OliverWestby Retired Dormant Member Join Date: Sep 2005 Location: England Posts: 16	General Electric Company Television I have recently bought a GEC model b.t.321 valve television, however, I have been unable to find any information what so ever on the internet about this. Does anyone have any information about this set, and if possible, a schematic and a list of the capacitors that need replacing. Thanks Oliver

10th Feb 2006, 9:10 pm	#8
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: General Electric Company Television As well as the puzzling lack of flywheel sync, it also puzzles me how on earth it could have been worthwhile them creating 6 different versions, each populated with different combinations of fitted channel coils - one with "all" channels (1..5,8..11) ? The versions are indentified by a colour code on the aerial panel, so before cracking on with the set it might pay to make sure you have an appropriate modulator. I dunno, what a cheapskate company. Anyhow I've unearthed the manual and might be able to scan it if still required. TTFN, Jon PS The trader sheet gives the incorrect date, a letter from GEC in late June said that the consolette versions BT320/1 would be released"later in the year".

10th Feb 2006, 11:35 pm	#9
OliverWestby Retired Dormant Member Join Date: Sep 2005 Location: England Posts: 16	Re: General Electric Company Television Hey, Thanks for all your replies. My friend and I are into valve radios/televisions, and we are more keen in the novelty of making them work than selling them. My friend got a Bush TV43 for £3! If you could scan the service sheet for me that would be great. I would become a member of bvws, but as a student I don't have the money to do this. Oliver

11th Feb 2006, 6:21 pm	#10
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: General Electric Company Television You can download the manual here :- http://www.thevalvepage.com/tvmanu/gec/gec.htm It's all the way down the bottom of the page. TTFN, Jon