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Old 12th Aug 2017, 4:00 pm   #1
FERNSEH
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Default Gec 12" bt5144.

Electrically similar to the GEC BT2147 except for the 12" round triode CRT and having a box like wooden cabinet.
Here are the first pictures of the dismantled set.
Scary business removing the chassis from the cabinet as the CRT is not properly secured to the chassis, no metal band around the bowl of the tube, just a piece of co-ax cable. The mask is badly perished, it will be removed from the tube and turned 180 degrees so that the bad part is at the top and then the CRT and mask can be positioned safely on the lower metal supports. Also, must find a metal band for the CRT bowl
First job is repair that bashed chassis.

DFWB.
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Old 12th Aug 2017, 7:36 pm   #2
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Default Re: Gec 12" bt5144.

Looking good David! Very best of luck. Looks like we'll both be having similar issues with perished GEC shadow masks. That tube sits a lot further forward than on my 9" chassis.
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Old 12th Aug 2017, 8:40 pm   #3
MonochromeMarc
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Default Re: Gec 12" bt5144.

Hi David,

Well the chassis looks nice and grotty, should be fun !
What's the state of the cabinet ?

Marc.
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Old 12th Aug 2017, 8:57 pm   #4
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Default Re: Gec 12" bt5144.

Hi Matspar, The mask is pretty grotty and there's not much I can do with it although it's bit better now since I applied some linseed oil on it, the rubber has softened up somewhat.
Hi Marc,
The condition of the cabinet is not too bad, certainly there's no need to strip off the lacquer but that bashed up chassis is another matter....

DFWB.
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Old 12th Aug 2017, 10:15 pm   #5
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Default Re: Gec 12" bt5144.

Hi David,
I have a slightly better 12" GEC mask.
I might be able to pick it up in a couple of weeks if you are interested.

Cheers
Andy
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Old 13th Aug 2017, 12:12 pm   #6
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Default Re: Gec 12" bt5144.

Hi Andy,
Thanks for the offer of the mask. Another picture of the damaged chassis. The right side panel should be an easy metal bashing job to straighten it out. However, I do have some problems with main chassis section, it's badly twisted.

DFWB.
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Old 16th Aug 2017, 5:12 pm   #7
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Default Re: Gec 12" bt5144.

Managed to straighten out the twisted chassis by using pieces of wood and the appropriate force necessary to get the job done.

DFWB.
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Old 17th Aug 2017, 8:16 am   #8
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Default Re: Gec 12" bt5144.

Difficult to see how the chassis could get so twisted.
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Old 17th Aug 2017, 10:24 am   #9
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Default Re: Gec 12" bt5144.

I wonder how it got like that without smashing the cabinet or tube? A frustrated repairer?
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Old 17th Aug 2017, 12:33 pm   #10
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Default Re: Gec 12" bt5144.

I was almost tempted to break up this set for it's parts. However, now that the chassis is straightened up I reckon it has the potential to be a decent set. The correct securing strap has been found for the CRT so that loop of co-ax cable can go. Even that perished mask can be tidied up. Just need to find the tensioning springs for the CRT strap.
It's amazing how the CRT has survived to whatever happened to damage the chassis. It took a fair amount of force to straightened it up.

DFWB.
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Old 17th Aug 2017, 12:39 pm   #11
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Default Re: Gec 12" bt5144.

You do love a challenge! Rubber paint on the mask?
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Old 17th Aug 2017, 2:37 pm   #12
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Default Re: Gec 12" bt5144.

"Rubber paint on the mask? "

It is a bit shabby to say the least. Looking at the chassis it would appear that it hasn't received much attention during its lifetime. Just a couple of RadioSpares capacitors and that's it.

DFWB.
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Old 18th Aug 2017, 11:41 am   #13
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Default Re: Gec 12" bt5144.

And here is the reason why the CRT didn't implode when the set was damaged.
This is one robust tube. Evidence of that fact can clearly be seen around the periphery of the faceplate. The glass is very thick. Imagine if the CRT installed in this set was a Mazda CRM121? There would have been one almighty bang.

DFWB.
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Old 18th Aug 2017, 2:06 pm   #14
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Default Re: Gec 12" bt5144.

As robust as that Advance signal generator? !!!

Keep going David - I love your 'sagas' .... truly!
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Old 18th Aug 2017, 3:32 pm   #15
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Default Re: Gec 12" bt5144.

That old Advance signal generator has been in service for more than forty years and is still spot on for calibration, it's good enough for aligning radios and most TVs.
Tried to attach the CRT to the mask, it's just not going to happen, so my next idea is to install the trimmed up mask in the cabinet and the chassis mounted CRT will then butt against the mask.
Attachment shows the mask test fitted in the cabinet.

DFWB.
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Old 18th Aug 2017, 4:30 pm   #16
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Default Re: Gec 12" bt5144.

Where do these orphan puppies from David? Woodworm, bent chassis, modified chassis, liquid masks and backless...

That BT5144 should be an easy one David. Don't turn it into a saga worthy of Metro Goldwyn Mayer complete with 1000 extras..

Regards, John.
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Old 18th Aug 2017, 5:02 pm   #17
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Default Re: Gec 12" bt5144.

HKS wrote: "Don't turn it into a saga worthy of Metro Goldwyn Mayer complete with 1000 extras.."

Hi John,
Would I do that?

DFWB.
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Old 18th Aug 2017, 6:51 pm   #18
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Default Re: Gec 12" bt5144.

Four wood strips locate the safety glass and mask into position. Metal or wood clamps will be made to secure the assembly in situ.

DFWB.
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