VCR97 Project
 

Hello.
When I was just a nipper I remember my parents had a small tall TV, this tuned out to be a consol 12inch Viewmaster that my dad built prior to the family moving to Irvine in 1957. We moved from Station Avenue in Walton-on-Thames in a rented house from a Mrs Murray-Smith.
Prior to my dad building the Viewmaster he built a set that used a VCR97 which was built before I was born, my older sister remembers it well and watched the Queens coronation on it. When he built the Viewmaster he gave the VCR97 set to Mrs Murray-Smith.
Joe Urban in Anstruther also has a VCR97 set although not working, it was too expensive for me to buy.
I was totally taken aback on Sunday when Mickymushradio gave me a VCR97 CRT a chassis, plans and many other bits and pieces to make one of these sets.

This will be a great project which I will do with relish, I know it wont be done in a weekend but I hope to show progress on a weekly basis, I am not too sure if I will stick to the plans as I knowing my dad I doubt he would but I will give it my best shot. so watch this space and a huge thanks to Mike.

Re: VCR97 Project
 

I for one will be an avid follower Trevor and of course as a past builder of the Argus I can understand the appeal. ;)

Steve

Re: VCR97 Project
 

Looking forward to reading about progress.
Best of luck with it.

Frank

Re: VCR97 Project
 

Hi Trevor.
Great project, now that's what I call real vintage television.

What valve types does your set use?

DFWB.

Re: VCR97 Project
 

Hi.
I have had a look at the chassis and the mounts for the tube, I have tried everything for size etc, not that Mike is likely to make any errors as his workmanship is second to none.
Here are some pictures of the chassis then the CRT mounts in place and finally with the CRT in place.
I have taken other photos that I will use to work out a suitable layout and where to drill out more holes for tag strips, smoothing & any other valve base holes.
The project will also be interesting in that I can experiment with some of the lower line standards.
Watch this space.

Re: VCR97 Project
 

I envy you on creating a television set from scratch with an option to make your own cabinet.
I'm looking forward to your project on this thread and wish you a very best of luck.

Re: VCR97 Project
 

Looking good so far Trevor,

I'll be following this with interest!

Dom

Re: VCR97 Project
 

Hello,
Interesting project.
I seem to remember reading that VCR97s were made by different manufacturers and some could not display a full picture on the screen.
You should even be able to watch in colour - Green!
Good luck,
Yours, Richard

Re: VCR97 Project
 

Hi.
I would think that if the scanning was able to "fill" the screen that a full picture would be able to be seen, but who knows, indeed the phosphor is a green radar type although not of a particularly long persistance I have been led to believe.
My first part of construction will be power supplies then attention to the timebases and scanning plate drives.
I am not too sure yet about RF/IF, TRF or even just baseband input, perhaps people here could comment.

Re: VCR97 Project
 

Some early HMV and Marconi TV sets employed green phosphor CRTs.
The model numbers that used the green CRT were the console models HMV 903 and and the Marconi 704. The CRT was an Emiscope 6/1. which was a nine inch diameter, magnetic deflection and electrostatic focus tube.
Have you got the cabinet for your VCR97 receiver?

DFWB.

Re: VCR97 Project
 

Hello David
No cabinet but I think that will be a long way off.
Tonight I will be studying all the paperwork I got from mike and the photos I have taken then I will decide on the plan of attack, I may make a start tomorrow but the Cossor 926 may get attacked instead, "decisions decisions"!

Re: VCR97 Project
 

When you get it up and running i have another tube which will give you a B/W picture,i also have another couple of VCR97's some of the VCR97's did have a shadow on them due to manufacturing tolerances i beleive.
M.O. valveholders may be a bit of a problem if you go down the SP41/61 route but i have a couple of very scruffy Murphy's if you get stuck.

Mike

Re: VCR97 Project
 

Not true Trevor. Picture cut-off was a common fault in VCR97s. This was when the electron beam hit the deflection plates and was unable to carry on to the phosphor before a full raster was displayed.
Many adverts in the post-war mags guaranteed "full picture" or "no cut-off", which meant that this would not be a problem, at extra cost.

Re: VCR97 Project
 

Thanks Brian.
Thanks for the info, I really am not too clued up on electrostatic tubes I just have to except what I'm told, glad you have cleared it up for me.

Mike.
Thanks for the offer of the "white" tube, might be a few weeks though before there's a result.

Re: VCR97 Project
 

Details of the VCR97=CV1097= Mullard ECF60 CRTs.

Screen diameter is 6 inches = 252mm.
Heater volts 4 @1amp. Va1 200V. Va2 450V. Vg1 -100V.
Deflection sensitivities mm/V: X plate 0.3. Y plate 0.57. Va3 2000V.

CK12 base: Pin 1 grid. 2 cathode. 3 and 4 the heater. 5 No connection. 6 Anode2.
7 NC. 8 y2 plate. 9 x2. 10 Anodes 1 and 3. 11 x plate1. 12 y plate 1.

I'd guess that you will need 700V peak to peak for full horizontal scanning and 400V P-P for vertical scan. The timebases will need to operate from a 1000 volt supply. The timebase output valves operate in a push-pull manner

Then comes the decision to use a negative or positive EHT supply. It's a negative EHT supply the Argus receiver.

DFWB.

Re: VCR97 Project
 

Hello David.
Thanks for the info on the tube, I have been looking over various circuits last night and I have come to the conclusion of using the best of all worlds with this project and not to stick rigidly to one design. My aim today is to look at a Cossor 926 thats on the bench for an hour or so then to start on the power supply of the project. There are two mains transformers on the chassis so far so I will concentrate on the EHT supply to the tube and the various feeds to the tube. The EHT will be generated using a Cockcroft Walton multiplier from the 350-0-350 winding on one of the transformers.
Regarding plate drive I will use 6SN7's for both line and frame with the valves arranged as push pull drivers so I shouldn't need an HT of nearly 1000v for full scan.
While building the set I will draw out the diagram in stages and on completion re-draw the diagram as it will be in the final set.

Re: VCR97 Project
 

I expect this must be a CV2810, which has a longish persistence yellow-green phosphor backed by a short persistence violet one. The result is in effect a 'black and white' picture, but with green smearing on the action.

If I can naughtily slip in a quick request here, this didn't have much luck on the wanteds before, I am still looking for a good VCR517 or CV2810 tube for my Argus. The original has gone down.

Steve

Re: VCR97 Project
 

Hello.
Well it's been one of those days! Firstly the soldering iron started acting up, then the Cossor took up most of the day, now it's on the back burner as the tube is flat and one of the windings on the Frame o/p transformer is o/c, this is a set for a later day.
All I will do to the VCR97 set today is to fit a couple of tag strips and wire up the transformers.

Re: VCR97 Project
 

If I can naughtily slip in a quick request here... this didn't have much luck on the wanteds before...I am still looking for a good VCR517 or CV2810 tube for my Argus. The original has gone down:-X.

Hi Steve i think i did offer this one at the time but lend only as i have a Premier kit tv to restore and it is destined for that,i have a couple of 97's to use for restoration etc but would like the 2810 in it when restored.

Mike

Re: VCR97 Project
 

Hi Trevor,

Congratulations on your project.
I have recently completed building the Argus with inspiration from Radiocraft website. I still have a few niggles to sort out before connecting to the Aurora. eg I get a 3 volt AC potential difference between the chassis and an independant earth.
Hope the pics give you some inspiration.

Good luck and best wishes

Bob.