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Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

 
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Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by yampy187 » Tue Jan 19, 2016 10:32 am

Hi All.

Some of you might have seen the set in question mentioned in the suppliers and sources section. I was the successful bidder so I picked the set up yesterday.

It's in very good clean condition. The seller had already applied mains :stm: No bangs but it fires up of a fashion. On getting it home, I fed it a signal and was greeted with a partial picture. The sound is very good. From what I can see on the screen I should be looking for bad caps in the frame stage? There's a hell of a lot of those blue 'dubilier' Plastic capacitors present. I'm going to order a handful of new caps this week. The LOPT seems to be one of the earlier type with the overwind and not the jellypot variety, which remains cool to touch after 15 mins or so.

Does anyone have a service manual that i can have a copy of by any chance?

Thanks in advance.

Jan
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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by slidertogrid » Tue Jan 19, 2016 11:12 am

That's a very pretty set Jan, I saw it on e bay and drooled over it!
I would say that recapping will cure your frame faults. My 950 was full of the same capacitors and they were almost all leaky. The ones to watch are in the line output stage, leaky caps there can put undue stress on the lopt. I have had a few sets where leaky caps was causing the lopt to run hotter than normal, in one case much hotter!
I look forward to reading about it's progress.
:aad
Rich.

 
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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by Till Eulenspiegel » Tue Jan 19, 2016 11:34 am

This is a rare variant of the 900 series in having FM radio. Early production sets employed a similar type of line output transformer like the one that was employed in the 850 series. The 900 "Cool Chassis" was introduced in late 1964. The jellypot transformer appeared the following year.
The frame timebase fault could be as simple as the cathode bypass capacitor of the output valve having gone low capacity.

Till Eulenspiegel.

 
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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by ntscuser » Tue Jan 19, 2016 4:36 pm

Servicing the 900 chassis was covered in the August and September 1968 issues of Practical Television.

I don't have the August edition but the September issue (which includes the circuit diagram) can be downloaded from here:

http://www.americanradiohistory.com/Pra ... gazine.htm

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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by yampy187 » Tue Jan 19, 2016 7:38 pm

Thanks for the helpful replies everyone!

I'm yet to get the proper caps for the frame stage but i've tacked in a few close values and these are the results. will be making a trip to maplins tomorrow. I still have very intermittent vertical lock and the control is right up one end. also the picture bounces about quite a bit.

Very impressed by the sound quality i must say!

Jan
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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by Till Eulenspiegel » Tue Jan 19, 2016 9:40 pm

Does your set have the optional flywheel sync unit? Way back in the sixties I had a number of Ultra 6625 sets out on rental and these early production 900 series sets were not equipped with the flywheel unit.
Direct line sync was employed with a clever circuit to extend the pull in range of the line hold control.

Till Eulenspiegel.

 
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Re: Ultra Bermuda 6627 - BRC900 Series Dual Standard TV

Post by yampy187 » Tue Jan 19, 2016 10:57 pm

Till Eulenspiegel wrote:Does your set have the optional flywheel sync unit? Way back in the sixties I had a number of Ultra 6625 sets out on rental and these early production 900 series sets were not equipped with the flywheel unit.
Direct line sync was employed with a clever circuit to extend the pull in range of the line hold control.

Till Eulenspiegel.


Yes Till, It does.

A small square PCB with an EF80 on it?

This set is turning out to be a cracker! Tube is good too :aad


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