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Old 30th Oct 2017, 10:59 pm   #21
PaulM
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Default Re: Mystery Decca (CZ8150)

The neck on this tube is 38 mm.

I've found something interesting in this book:

Liberal Trade and Japan: The Incompatibility Issue
Contributions to Economics


Author: Marcel F. van Marion
Publisher: Physica-Verlag
Date: 1993

P175 gives a hint at the complex relationship between the UK government, Rank, Toshiba and Philips/Mullard. It seems that Toshiba wanted to buy the 30AX technology from Philips via Mullard, but were frustrated? It looks to me like they just copied it - at least experimentally. I think that this experimental tube bears witness to some interesting 'goings on' in the UK TV industry of the time!

Thanks, Robin, I had seen reference to 150V for the 110 and that tallies with your information. However, at 150V the width and range of E-W pincushion is inadequate. At 165V the E-W pincushion is not clipped and there's enough width. It seems happy there.

This set is a mongrel - looks like the CZ8150 but has teletext and a Toshiba '30AX'. No wonder there's no identification of any kind!

Best regards,

Paul M
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Old 31st Oct 2017, 10:47 am   #22
FERNSEH
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Default Re: Mystery Decca (CZ8150)

In-line gun 110 degree Toshiba CRTs were fitted in the Bush Z718 series of colour TV sets.
Didn't these CRTs have 38mm necks? I kinda remember seeing a thick neck on the CRT employed in the 18" model, the BC6100.
Toshiba CRTs fitted in Decca 70 and 90 series TVs had the 28.5mm neck.
The CZ8150 most likely used a version of the 110 chassis, the chassis that employed the 30AX CRT.

DFWB.
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Old 31st Oct 2017, 11:09 am   #23
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Default Re: Mystery Decca (CZ8150)

Imagine if Toshiba had been able to make 30AX CRTs - the K30s and TX10s would still be going strong now!
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Old 31st Oct 2017, 9:05 pm   #24
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Default Re: Mystery Decca (CZ8150)

I just re-read the topic from start, it seems I had already responded back then. I would be very interested in some detailed pictures of the picture tube to examine the link with Philips. The label and any printing or stamping on the cone/bell, but maybe some details such as the cannon and the deflection yoke would be nice as well.
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Old 31st Oct 2017, 10:06 pm   #25
PaulM
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Default Re: Mystery Decca (CZ8150)

I think that your initial suspicions were correct about the CRT! The question really is whether it was 'reverse engineered' or an 'authorised' copy. I suspect the former.

There's no printed labels, serial numbers or anything to be seen anywhere and you can't see much of the neck itself. I'm not in a position to take any more photos for a week or more (complicated), but I will in due course.

It would be informative to find a Toshiba data sheet for the tube, but Japanese CRT data has always been difficult to come by. Richardsons (see: www.rell.com ) used to have a great library of these things but I've lost my contact there. I don't even think that they have any interests in CRTs these days.

Best regards,

Paul M
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Old 3rd Nov 2017, 10:49 pm   #26
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Default Re: Mystery Decca (CZ8150)

Thanks! I'll wait a bit, lots of other stuff to tend to anyway.

The reason I asked for stamping on the cone, is that this was the way Philips marked their tubes. It the tube was assembled by Philips/Mullard and then labeled Toshiba, such markings would be present. Also if Philips/Mullard had a second source agreement with Toshiba they may have required such markings be present for their own labeling logistics.
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Old 6th Nov 2017, 5:59 pm   #27
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Default Re: Mystery Decca (CZ8150)

Hello Maarten,

Attached is a close-up picture of the strange flangeless 30AX like Toshiba 26" CRT in this Decca. It is different to a 30AX as it has convergence/purity rings, but it is of flangeless construction which I believe was one of the key features of the 30AX system. This page has a lot of patent and explanatory details about the 30AX: http://obsoletetellyemuseum.blogspot...ssis-80_5.html

I would be very interested in your views on this tube. The yoke does actually have a TDK number stamped on it, so Japanese sourced ferrite, I guess.

It's definitely a 38 mm neck - I've just checked again.

Removing the yoke may reveal what sort of level of correction windings there are inside, but I'm a bit loathe to mess with it as it's probably nothing like as accurate as a real 30AX in terms of set up.

Looks to me like it's work in progress.

Best regards,

Paul M
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Old 6th Nov 2017, 9:24 pm   #28
FERNSEH
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Default Re: Mystery Decca (CZ8150)

Many service engineers will remember that some rebuilt 30AX CRTs were supplied with static convergence and purity magnets.
The picture reveals there is no 30AX technology in the 660AB22 tube. A real 30AX tube does not have any external magnets.

DFWB.
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Old 6th Nov 2017, 9:32 pm   #29
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Default Re: Mystery Decca (CZ8150)

What about the flangeless technology - is that not part of the 30AX technology? The patent abstract says:

30AX is a new in-line color TV display system with 110 deflection angle and interchangeable tubes and yokes. It is based on the production experience gained with the 20AX system introduced in 19741,2,3) and the results of further investigation in the field of tube technology and deflection yoke design. For the tube, this meant a new reference system, an internal magnetic correction ring and an improved gun design. For the yoke, the most important elements are a new "flangeless" winding technology, a change in the shape of the windings at the screen side of the line deflection coil and the use of field shapers embedded in the deflection coil.

There are surely elements of 30AX technology there - are there not? The external magnets are not the whole story - it's more complicated than that.

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Old 7th Nov 2017, 12:18 am   #30
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Default Re: Mystery Decca (CZ8150)

While the internal placement and semi-automated magnetizing process of the static adjustment rings was certainly part of the 30AX technology, I don't consider it essential, especially not since this tube is a pre production sample (external rings might have been planned for bulk production). The yoke technology looks like a Japanese clone (copy, imitation, interpretation) of the Philips design. On first sight, I would say the tube was likely built by Toshiba under license of at least some of the 30AX patents but not showing any obvious Philips sourced parts.

@FERNSEH: Do I interprete correctly if I think you're saying that a rebuilt 30AX isn't a 30AX anymore if the rebuilder used external rings?
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Old 7th Nov 2017, 10:06 am   #31
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Default Re: Mystery Decca (CZ8150)

Thanks, Maarten - that's very interesting and seems to fit the historical trail that Toshiba wanted 'in' on 30AX either by the front door or the back door.

On the question of magnets, there is this strange Telefunken 30AX with magnets (of a sort!), from new. See: http://obsoletetellyemuseum.blogspot...mory_4352.html

Perhaps the 30AX alignment as supplied wasn't good enough for them?

BTW, the 'Obsolete Tellye' website is a mine of background information and TV set history.

Best regards.

Paul M
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Old 7th Nov 2017, 11:59 am   #32
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Default Re: Mystery Decca (CZ8150)

The tube regunners didn't use genuine Philips 30AX gun assemblies.

DFWB.
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Old 7th Nov 2017, 1:15 pm   #33
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Default Re: Mystery Decca (CZ8150)

That's interesting, also in general. What gun assemblies did they actually use?
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Old 7th Nov 2017, 1:17 pm   #34
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Default Re: Mystery Decca (CZ8150)

Quote:
Originally Posted by Maarten View Post
(external rings might have been planned for bulk production)
This should have read: (internal rings might have been planned for bulk production)
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