Name that set- Halloween Special! - UK Vintage Radio Repair and Restoration Discussion Forum

Colourstar · 26th Oct 2014, 2:27 pm

Not for the faint-hearted, a very spooky looking set to identify here, but there are clues to be seen behind the terrifying cobweb collection... This remarkable television has spent many years entombed in an attic and retains it's original fabric covered flex and 2-pin plug.

'Ghost(ing) Whisperer' Fernseh and some other forum fiends, sorry friends, are visiting tomorrow, so it's hoped that this set may be showing an otherworldly glimmer on screen before darkness falls...

I doubt we will be able to contact 'the other side' though as this is a single channel set and has never seen ITV!

We are expecting to come across a few stakes and garlic during the course of the day... but only during our pub lunch.

Steve

(cue screams / thunder & lightning fx /maniacal laughter etc

)

Heatercathodeshort · 26th Oct 2014, 3:24 pm

Well it was made by Plessey [Mk 1 chassis] with radio. Could be a Defient or derived type. John.

G6Tanuki · 26th Oct 2014, 5:23 pm

Don't let daylight get to it or it will let out one final blood-curdling shriek of line-whistle and crumble to dust!

Sideband · 26th Oct 2014, 5:44 pm

What a fantastic set! I can already hear the echoing laughter as ,late one night after operating on the set, the big switch is closed for the first time.....!

McMurdo · 26th Oct 2014, 7:03 pm

That's the best condition in which to disinter a vintage set. You normally pay extra for dust and cobwebs. Looking forward to seeing the front

Restoration73 · 26th Oct 2014, 7:53 pm

I can't remember if the cobwebs are insulated or provide the EHT discharge path.

Duke_Nukem · 26th Oct 2014, 7:59 pm

wouldn't be Regentone by any chance ? TR20 ?

TTFN,
Jon

Mikey405 · 26th Oct 2014, 8:37 pm

I think I know what this is so I will keep my mouth shut. Make sure you post some pictures up here after your Halloween meetup Steve.

Colourstar · 26th Oct 2014, 8:45 pm

OK, time to reveal all:

It's a Philco BT1840.

More tomorrow.....

FERNSEH · 26th Oct 2014, 11:18 pm

Very American in appearance, well it is a Philco. Super reliable Plessey chassis.
Great looker.
All those cobwebs. Very Addams Family or Munsters.

DFWB.

neil29 · 27th Oct 2014, 12:55 am

I had one of these

. but it was in a sorry state compared to yours

.

Cheers
Neil.

mark pirate · 27th Oct 2014, 9:43 am

What a great looking set, just as we like to find them

It looks in super condition under all those cobwebs, I bet it has not seen the mains in over 50 years, be gentle with it.

Mark

Colourstar · 27th Oct 2014, 7:04 pm

A quick update on work in progress. We have screen illumination, but no frame oscillation yet (soon will have though!) The Ferranti crt looks OK.

The set came to life with no hissy fits despite its decades of dormancy. A grand old lady!

More later...

Steve

Colourstar · 27th Oct 2014, 10:50 pm

With the North East crew heading home it's time to reflect on a productive afternoon. At close of play we had a full raster,of moderate brightness but poor focus. Progress stalled there as we could achieve neither sound or vision no matter how loud the Aurora shouted. Although the set is labelled 'London' we tried all the Band 1 channels just in case it had been tweaked. It hadn't.

A meter probe could be made to provoke plenty of jumping and flashing on screen and various noises through the speaker, but somewhere the signal from the aerial socket is being lost. Touching the inner contact of the aerial socket causes faint pops to be heard. No caps have been changed on the signals side, but David suspects the problem may be more fundamental than that. The coils are unusual, being plug-in ones on B9A valve bases. None of the coils were found to be open circuit. The investigation continues.

My thanks to David, Brian and Gary for their sterling efforts today. A long-term project is kick-started.

A couple of pics of work in progress follow, the most alarming of which shows the rather undignified up-ending of the set to access under the chassis! No way to treat an old lady! The lack of width on 'first light' was due to the scan coils having slid away from the bulb of the tube.

Steve

julie_m · 28th Oct 2014, 2:25 am

That doesn't sound like anything that a few component replacements won't sort out. You've got some sort of deflection, both vertical and horizontal. And if you can get some influence from probing about, that means most of it must more or less work, nearly.

I might have to have a go at a television myself sometime. In my younger days, I found the idea of a live chassis too frightening; not so much anymore.

Focus Diode · 28th Oct 2014, 9:08 am

A great day out and great to have seen life restored to this old set almost in time for halloween, even if it's currently giving only a defocused raster.

More pics to enjoy, the second picture shows the chassis underside before any components were replaced.

Cheers
Brian

Heatercathodeshort · 28th Oct 2014, 9:11 am

Who are that strange collection of television receiver wreckers that don't appear to know which way up the cabinet should be. Obviously you have been working on that upside down Defiant for far too long. Not all receivers employing the Plessey chassis have their tubes at the bottom...

Very interesting receiver and one I'm not familiar with. That Plesssey chassis must be the easiest to get 'first light' on than any other chassis. The tube looks great.
The double D mask looks like a 16" metal cone job but I didn't think the Plessey chassis was capable of driving one. I presume it's a 12"?
[PS Just seen the ion burn. A Ferranti triode. Quite a rare tube. ]
Good luck with it. John.

mark pirate · 28th Oct 2014, 9:19 am

Great progress, I am sure that some new capacitors will bring the old girl to life.
Nice to see the CRT is good, it is amazing how well they can wake up after a bit of use, even the ion burn becomes less noticeable!

Mark

FERNSEH · 28th Oct 2014, 7:40 pm

We certainly made good progress with the electronic restoration. Starting with the radio chassis which is a Philco made unit. The radio chassis is a modified B2810. What came as surprise was the capacitive heater supply dropper. It's C32 on the attached circuit diagram, 2.7 microfarads.
Having got the radio working in a fashion we moved on to the TV. That not so thin white came along with out too much trouble. Next for attention was the frame timebase. Having established that the frame amplifier was working my attention was drawn to the oscillator which is a cross coupled multi-vibrator employing a Brimar 6SN7GT double triode. It was found that an anode load resistor R80 (1.5Megohms) was OC. Feedback capacitor C47 (0.05mfd) and ramp forming capacitor C49 (0.05mfd) were leaky and were replaced. Interestingly, it seems that the capacitors were service replacements fitted way back in the fifties.
The big disappointment was the fact I couldn't make the RF chassis work.
This unit differs from the usual Plessey Mark 1 RF deck in as much it employes miniature Brimar 8D3 pentodes instead of the usual Mazda 6F13 or 6F1.
The RF unit employs plug in coil assemblies which are similar to those found in the Philips 1101U and 1200U TV receivers.
I believe that the mixer-oscillator is active because there is a negative voltage present at the control grid of the valve.
We'll not give up on the RF unit. I suppose a replacement one can be fitted but it is a special made for Philco RF unit and is different to the Mazda valve version fitted in Defiant and Regentone sets.

DFWB.

FERNSEH · 29th Oct 2014, 1:36 am

Check out post #16 of this topic and the second attached picture showing the underside of the chassis. Note the four trimmers on the right side of the RF sub-chassis. We are certain that these are the factory fitted components.
The trimmers are neat little 10pF variable capacitors with fixed and screw driver adjustable vanes. Not fitted on RF decks with the conventional RF coils.

DFWB.

26th Oct 2014, 3:24 pm	#2
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Name that set- Halloween Special! Well it was made by Plessey [Mk 1 chassis] with radio. Could be a Defient or derived type. John.

26th Oct 2014, 5:23 pm	#3
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Name that set- Halloween Special! Don't let daylight get to it or it will let out one final blood-curdling shriek of line-whistle and crumble to dust!

26th Oct 2014, 5:44 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: Name that set- Halloween Special! What a fantastic set! I can already hear the echoing laughter as ,late one night after operating on the set, the big switch is closed for the first time.....! __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

26th Oct 2014, 7:03 pm	#5
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,274	Re: Name that set- Halloween Special! That's the best condition in which to disinter a vintage set. You normally pay extra for dust and cobwebs. Looking forward to seeing the front __________________ Kevin

26th Oct 2014, 7:53 pm	#6
Restoration73 Nonode Join Date: Jun 2013 Location: Surbiton, SW London, UK. Posts: 2,801	Re: Name that set- Halloween Special! I can't remember if the cobwebs are insulated or provide the EHT discharge path.

26th Oct 2014, 2:27 pm	#1
Colourstar Octode Join Date: Feb 2006 Location: Ilkeston, Derbyshire, UK. Posts: 1,398	Name that set- Halloween Special! Not for the faint-hearted, a very spooky looking set to identify here, but there are clues to be seen behind the terrifying cobweb collection... This remarkable television has spent many years entombed in an attic and retains it's original fabric covered flex and 2-pin plug. 'Ghost(ing) Whisperer' Fernseh and some other forum fiends, sorry friends, are visiting tomorrow, so it's hoped that this set may be showing an otherworldly glimmer on screen before darkness falls... I doubt we will be able to contact 'the other side' though as this is a single channel set and has never seen ITV! We are expecting to come across a few stakes and garlic during the course of the day... but only during our pub lunch. Steve (cue screams / thunder & lightning fx /maniacal laughter etc ) Attached Thumbnails

26th Oct 2014, 7:59 pm	#7
Duke_Nukem Octode Join Date: Jan 2003 Location: Birmingham, West Midlands, UK. Posts: 1,268	Re: Name that set- Halloween Special! wouldn't be Regentone by any chance ? TR20 ? TTFN, Jon

26th Oct 2014, 8:37 pm	#8
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Re: Name that set- Halloween Special! I think I know what this is so I will keep my mouth shut. Make sure you post some pictures up here after your Halloween meetup Steve. __________________ G7TRF

26th Oct 2014, 8:45 pm	#9
Colourstar Octode Join Date: Feb 2006 Location: Ilkeston, Derbyshire, UK. Posts: 1,398	Re: Name that set- Halloween Special! OK, time to reveal all: It's a Philco BT1840. More tomorrow..... Attached Thumbnails

26th Oct 2014, 11:18 pm	#10
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Name that set- Halloween Special! Very American in appearance, well it is a Philco. Super reliable Plessey chassis. Great looker. All those cobwebs. Very Addams Family or Munsters. DFWB.

27th Oct 2014, 12:55 am	#11
neil29 Heptode Join Date: Dec 2004 Location: Newport, Gwent, UK. Posts: 962	Re: Name that set- Halloween Special! I had one of these . but it was in a sorry state compared to yours . Cheers Neil.

27th Oct 2014, 9:43 am	#12
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Name that set- Halloween Special! What a great looking set, just as we like to find them It looks in super condition under all those cobwebs, I bet it has not seen the mains in over 50 years, be gentle with it. Mark

27th Oct 2014, 7:04 pm	#13
Colourstar Octode Join Date: Feb 2006 Location: Ilkeston, Derbyshire, UK. Posts: 1,398	Re: Name that set- Halloween Special! A quick update on work in progress. We have screen illumination, but no frame oscillation yet (soon will have though!) The Ferranti crt looks OK. The set came to life with no hissy fits despite its decades of dormancy. A grand old lady! More later... Steve

27th Oct 2014, 10:50 pm	#14
Colourstar Octode Join Date: Feb 2006 Location: Ilkeston, Derbyshire, UK. Posts: 1,398	Re: Name that set- Halloween Special! With the North East crew heading home it's time to reflect on a productive afternoon. At close of play we had a full raster,of moderate brightness but poor focus. Progress stalled there as we could achieve neither sound or vision no matter how loud the Aurora shouted. Although the set is labelled 'London' we tried all the Band 1 channels just in case it had been tweaked. It hadn't. A meter probe could be made to provoke plenty of jumping and flashing on screen and various noises through the speaker, but somewhere the signal from the aerial socket is being lost. Touching the inner contact of the aerial socket causes faint pops to be heard. No caps have been changed on the signals side, but David suspects the problem may be more fundamental than that. The coils are unusual, being plug-in ones on B9A valve bases. None of the coils were found to be open circuit. The investigation continues. My thanks to David, Brian and Gary for their sterling efforts today. A long-term project is kick-started. A couple of pics of work in progress follow, the most alarming of which shows the rather undignified up-ending of the set to access under the chassis! No way to treat an old lady! The lack of width on 'first light' was due to the scan coils having slid away from the bulb of the tube. Steve Attached Thumbnails

28th Oct 2014, 2:25 am	#15
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Name that set- Halloween Special! That doesn't sound like anything that a few component replacements won't sort out. You've got some sort of deflection, both vertical and horizontal. And if you can get some influence from probing about, that means most of it must more or less work, nearly. I might have to have a go at a television myself sometime. In my younger days, I found the idea of a live chassis too frightening; not so much anymore. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

28th Oct 2014, 9:08 am	#16
Focus Diode Octode Join Date: Jan 2006 Location: Borough of Gateshead, UK. Posts: 1,420	Re: Name that set- Halloween Special! A great day out and great to have seen life restored to this old set almost in time for halloween, even if it's currently giving only a defocused raster. More pics to enjoy, the second picture shows the chassis underside before any components were replaced. Cheers Brian Attached Thumbnails

28th Oct 2014, 9:11 am	#17
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Name that set- Halloween Special! Who are that strange collection of television receiver wreckers that don't appear to know which way up the cabinet should be. Obviously you have been working on that upside down Defiant for far too long. Not all receivers employing the Plessey chassis have their tubes at the bottom... Very interesting receiver and one I'm not familiar with. That Plesssey chassis must be the easiest to get 'first light' on than any other chassis. The tube looks great. The double D mask looks like a 16" metal cone job but I didn't think the Plessey chassis was capable of driving one. I presume it's a 12"? [PS Just seen the ion burn. A Ferranti triode. Quite a rare tube. ] Good luck with it. John.

28th Oct 2014, 9:19 am	#18
mark pirate Dekatron Join Date: Mar 2008 Location: Worthing, West Sussex, UK Posts: 5,185	Re: Name that set- Halloween Special! Great progress, I am sure that some new capacitors will bring the old girl to life. Nice to see the CRT is good, it is amazing how well they can wake up after a bit of use, even the ion burn becomes less noticeable! Mark

28th Oct 2014, 7:40 pm	#19
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Name that set- Halloween Special! We certainly made good progress with the electronic restoration. Starting with the radio chassis which is a Philco made unit. The radio chassis is a modified B2810. What came as surprise was the capacitive heater supply dropper. It's C32 on the attached circuit diagram, 2.7 microfarads. Having got the radio working in a fashion we moved on to the TV. That not so thin white came along with out too much trouble. Next for attention was the frame timebase. Having established that the frame amplifier was working my attention was drawn to the oscillator which is a cross coupled multi-vibrator employing a Brimar 6SN7GT double triode. It was found that an anode load resistor R80 (1.5Megohms) was OC. Feedback capacitor C47 (0.05mfd) and ramp forming capacitor C49 (0.05mfd) were leaky and were replaced. Interestingly, it seems that the capacitors were service replacements fitted way back in the fifties. The big disappointment was the fact I couldn't make the RF chassis work. This unit differs from the usual Plessey Mark 1 RF deck in as much it employes miniature Brimar 8D3 pentodes instead of the usual Mazda 6F13 or 6F1. The RF unit employs plug in coil assemblies which are similar to those found in the Philips 1101U and 1200U TV receivers. I believe that the mixer-oscillator is active because there is a negative voltage present at the control grid of the valve. We'll not give up on the RF unit. I suppose a replacement one can be fitted but it is a special made for Philco RF unit and is different to the Mazda valve version fitted in Defiant and Regentone sets. DFWB. Attached Thumbnails

29th Oct 2014, 1:36 am	#20
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Name that set- Halloween Special! Check out post #16 of this topic and the second attached picture showing the underside of the chassis. Note the four trimmers on the right side of the RF sub-chassis. We are certain that these are the factory fitted components. The trimmers are neat little 10pF variable capacitors with fixed and screw driver adjustable vanes. Not fitted on RF decks with the conventional RF coils. DFWB. Last edited by FERNSEH; 29th Oct 2014 at 2:04 am.