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The HMV 902: A TV-radiogram made in 1937.

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Till Eulenspiegel
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Behold the mighty HMV 902 TV-radiogram combination. Introduced in 1937 this huge set cost 120 guineas!  For that kind of money you could buy a new car.

This is the set I mentioned to in the Decca cabinet topic.  The CRT is an Emiscope 9" diameter electrostatic gun type and as the pictures show it is mounted in a vertical position and viewed by means of a mirror and a magnifying lens.  This arrangement was replaced in 1938 by a direct view 12" CRT, the new set was redesigned as model 902A.  

The model 902 is electrically similar to the model 900, the radio unit was modified so that the gram can be selected by  a four position function switch.  The TRF and timebase unit is almost identical to that in the 900, same goes for the power supply unit. An EMI automatic record player deck fitted, it's a beautifully over engineered unit

The 902A differs because the 12" Emiscope type 6/7 CRT has a much wider deflection angle. EMI called the new CRT the "Onion Tube". The timebases were redesigned to deliver the extra scanning power for the 57 degree CRT.  The then all new KT44 line output valve was first employed in the 902A.

Till Eulenspiegel.

HMV902_1.jpgHMV902_2.jpgHMV902_3.jpg

 
Posted : 21/08/2017 5:09 pm
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acj1980
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wooow what a amazing TV radiogram furniture, i never seen one like this in real life, but i am a real fan of it, the cabinet is so much thirties design, in danish the design from the thirties is called "funkis" .

Alex 😉 

 
Posted : 21/08/2017 5:41 pm
Anonymous
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I wich to fix a TV like this. But in DK we first got real TV in the erly 50'.

It's a fantastic "funkis-monster"

thumb_gif

 
Posted : 21/08/2017 6:07 pm
Nuvistor
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The assembly on the CRT neck, is that for focus if the crt is electrostatic?

 

It looks as the the neck narrows going through that assembly, is it permanently attached?

120 Gns, small fortune, working mans wage, perhaps  £2-3 pounds a week.

Not be many of those around, couldn't have sold many.

Frank

 
Posted : 21/08/2017 7:45 pm
PYE625
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A remarkable set and an informative description as ever Till  thumb_gif

To understand the black art of electronics is to understand witchcraft. Andrew.

 
Posted : 21/08/2017 7:49 pm
Marc
 Marc
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Hi Till, 

That's one heck of a beast, I bet you don't fancy moving it around in a hurry !

What's it's working status at the moment ?

Marc.

Marc
BVWS member
RSGB call sign 2E0VTN

 
Posted : 21/08/2017 9:07 pm
Till Eulenspiegel
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When one considers that the development of the CRT must have started sometime in 1935 it is a surprisingly advanced design.   The deflection is magnetic and the focusing is electrostatic.  The actual CRT gun assembly is quite large compared with a mid fifties electrostatic focus tube such as the Mullard AW43-80 which had the standard 38mm neck. 

The neck of the Emiscope tube is much narrower at the deflection coils.

The set hasn't switched on for a considerable time, let's find how it performs.

EMI was an affiliate company of the Radio Corporation of America.

This early RCA TV receiver was a very advanced design for 1931:     http://www.earlytelevision.org/rca_1932.html

Till Eulenspiegel.

 
Posted : 21/08/2017 9:32 pm
Katie Bush
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Ah, I remember it now!

That is one almighty skyscraper for a picture so small. It almost begs me to wonder why, on such a long CRT, did they not go for electrostatic deflection, unless as you say, it was because of its 'advanced' design.

In my best "Eccles" voice..... "Ohh, Oi wouldn't mind livin' in a house loike dat........"

 
Posted : 21/08/2017 10:21 pm
Till Eulenspiegel
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Hi Marion,  It just beggars belief that how such a monster of a TV set has such a tiny CRT.  Although the RGD 2347T has a 12" CRT it also is a monster of a set, and unbelievably over engineered, this thing has the biggest power pack ever fitted into a television set.  Will post up some pictures of it tomorrow.

The attachment shows the complex hexode gun assembly in the first generation Emiscope CRTs.  

Till Eulenspiegel.

HMV902_4.jpg

 
Posted : 21/08/2017 11:00 pm
peterscott
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A patented electron gun with high sensitivity.

  http://www.nostalgiatech.co.uk/new_page_8.htm

Peter

www.nostalgiatech.co.uk

 
Posted : 22/08/2017 8:42 am
Anonymous
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That looks like a rare looking beast! There can't be many of those still around. What are they worth today?

 
Posted : 23/09/2018 2:25 pm
Till Eulenspiegel
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Till Eulenspiegel is back.    

Last month the timebase chassis was removed to tidy up some of the so called restoration work done on the set in the 1980s and 1990s. What was acceptable then is not acceptable now. Those yellow capacitors had to be removed and replaced with restuffed EMI or other early capacitors such as those made by TCC.  The chassis will be reinstalled and tested. I'll report back the results from all this work.

Last year the correct EMI record deck was fitted.   Over the thirty years I've owned the set I've been always been on the lookout for better components and assemblies in order to bring the set up to it's ex-factory condition.  I'm still on the look out for the correct power unit. The unit presently fitted is OK but it's not exactly like the original. Might even consider having a replica of the power unit chassis made for the set.

TillEulenspiegel.

 
Posted : 03/10/2018 10:34 am
Nuvistor
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Good to see you back David.  ? 

Frank

 
Posted : 03/10/2018 10:43 am
peterscott
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Posted by: Nuvistor

Good to see you back David.  ? 

For me too, and great that you are working on the 902. Jac had a very nice power supply chassis made to replace the rusted out one in his 702.

Peter

www.nostalgiatech.co.uk

 
Posted : 03/10/2018 10:53 am
Till Eulenspiegel
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Hi everyone, 

It good to be back on the VRAT Forum again, and if you think about it this the forum for all matters to do with pre-war TV.  The sadly missed Brian Cuff was the chief exponent of all pre-war TV subjects on this forum so I think we owe it to his memory to keep contributing more topics about these early TVs.

Till Euenspiegel.

 
Posted : 03/10/2018 11:45 am
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