Wireless World 1964 Oscilloscope

[Ed_Dinning]

Hi David, I think your flying spot scanner was in one of the FJ Camm books such as Practical TV servicing manual from the 50's. I believe it also appeared in Prac TV..

For LF oscillograph work, with a locked waveform (power frequency studies), a Blue with afterglow phosphor works well.

Just checked my data book. Most VCR97's have 3 wires from internal electrodes connected to pin 7 for A2 focus, but to have normal focussing you should link pins 5,7,10 together. Remove the bakelite plate from the rear of the tube and you should be able to see the connections

Ed

[djrm]

Thanks for the book information Ed, I'll try and track down a version.
Yes all three of those terminals are connected, and of course this 'scope used to work wired as it is now anyway. I've had a peek under the cover too when I tried swapping the tube for the small one.
Yes I found the blue/yellow tube quite acceptable most of the time when it was in my old 'scope.
Kind regards, David.

[djrm]

I have found a design by J. G. Ransome in the Jan,Feb,March,April issues of Practical Television, with a little extra info in the June issue p407 too.

https://worldradiohistory.com/UK/Practical-Television/search.cgi?zoom_sort=0&zoom_xml=0&zoom_query=1964

[peter scott]

Hi Peter,
Thanks, I'm not familiar with the 517 and had to look it up.
I found these useful tables detailing the various old CRTs: https://frank.pocnet.net/other/docs/CRT-data.pdf
Is the 517 one of the blue with yellow afterglow types. I used to have one. The blue image was very sharp, much better than the VCR97 I had at the same time.
I would be happy with any and am in no great hurry.
Since I do not leave the county very often a forum relay transport would be very useful for me if it could get one nearer to my home in North Yorkshire.
Kind regards, David

Hi David,

I thought I had three of these things but one of them is a strange little tube with a contact in the middle of the screen.

As a teenager I bought an H2S display unit that I intended to turn into a film scanner. I believe it is a VCR517. If my 50 years ago memory is correct, then yes it does have a blue image with yellow afterglow. The other one I inherited about 5 years ago and it looks identical to my H2S one. Both have the Mu metal screen and base and rubber screen frame. I don't know where the number is but I would assume it too is a 517.

Are you a member of the Stenning forum? If not I can put a transport request on there.

Peter.

[djrm]

Are you a member of the Stenning forum? If not I can put a transport request on there.
Peter.

Hi Peter, No I'm not a member of the Stenning forum. I'd be happy for you to put a request in there on my behalf.

I used to have a strange radar tube with a middle contact. I always wanted to get it working but now I've lost it too.
Recently I saw a photo of the radar display it came out of. It had series of concentric rings with angle ticks on it. About 4 inch diameter, is that the one?

edit2, something like this: 
http://warbirdinformationexchange.org/phpBB3/viewtopic.php?f=3&t=51671

Kind regards, David.

[ppppenguin]

The only CRTs I know with a contact in the middle of the screen are monoscopes. Used to generate TV testcards in years gone by.

[djrm]

Jeffrey, looking at the page I posted with the picture of the radio altimeter it doesn't seem to have any electrical connection to the centre of the screen. I'd assumed it was some kind of funky polar display feature. maybe not. David.

[peter scott]

Hi David,

Yes, that might be the strange CRT with the centre connector. It has an RCA stamp on the base.

   

You are welcome to both tubes if you want them. Please let me know and I'll word a transport advert.

Kind regards,

Peter

[ppppenguin]

That's a strange CRT. Not like any monoscope tube I've seen. Could it have been part of some kind of scan converter system? Polar to rectangular? I'm also thinking of a possible variant of the WiIliams tubes that were used as "RAM" in a few early computers. The original Williams tubes didn't have such a connection: https://en.wikipedia.org/wiki/Williams_tube Or perhaps it was a special, made for a research project, for reasons now long forgotten. I'm sure Tektronix would have made all sorts of odd "one off" CRTs for R&D uses.

[peter scott]

I'm more convinced by David's SCR 718 Absolute Altitude Radar Display.

   

Peter