Using "Z" Mod on a scope.

[Murphyv310]

Hi Frank.
No that isn't a shameful effort. In fact it is interesting as surely all you are seeing is the video input modulated with hum and you then get a ghostly image like you see.
When I was 16-17 I saw this odd effect on a scope and it must have been 7-8 years ago I replicated it and got the theory explained to me.

           

[Murphyv310]

Hi.
Fitted a better CRT today and modified a function generator I got from a member here a few weeks ago for a sync input.
On the triangular output and synced up the linearity is reasonable, but no interlace, hardly a problem on the scope screen.
Next is to make a sync separator for composite video sources.

       

[ppppenguin]

Some years ago at Harpenden we had a mini demo of standards conversion. Jim Beacon G1JBG (anyone knw what happened to him? ) showed a version of Kat Manton's "MythTV" PC based Linux converter including using a 'scope as a display. Notes still on his website: http://www.g1jbg.co.uk/tektv.htm

It's hardly a new idea though not many folk would have had a 'scope back in 1941: http://www.earlytelevision.org/pdf/r-n_1-41.pdf

The great thing about using electrostatic deflection for small displays and narrow deflection angles is that the timebases are very easy and can readily work over a wide range of frequencies.

[Alistair D]

Jim Bacon still has a website complete with an email address.

http://www.g1jbg.co.uk/service.htm

Al

[ppppenguin]

His website was last updated in 2011, according to a notice on the home page. I have tried unsuccessfully to contact him by email on several occasions since he disappeared, though not recently. He came to my house on at least one occasion, to collect equipment. He worked for air traffic control, formerly at West Drayton, then at Swanwick. Enquiries on other forums have led nowhere.

I think Kat Manton has also disappeared from view. She and Jim can both be seen on last photo on this page photo, taken at the NVCF in 2006 when we had a large display of vintage TVs:
http://www.bvws.org.uk/events/photos/200...elevision/

Jim's 'scope display of 240 line pictures: http://www.g1jbg.co.uk/fothtv.htm

[`FRANK.C]

Hi.
Fitted a better CRT today and modified a function generator I got from a member here a few weeks ago for a sync input.
On the triangular output and synced up the linearity is reasonable, but no interlace, hardly a problem on the scope screen.
Next is to make a sync separator for composite video sources.

Hi Trevor

It's looking good.
If you wanted interlace you could try syncing to the falling edge of the field sync pulse you should get interlace as this edge varies by a half line for odd and even fields. But that edge occurs towards the end of the field blanking period so not ideal to sync off.

Frank

[Alistair D]

Jeffrey, his details are still listed on QRZ.com. Let me know if you want them. I am having feelings of deja vu but maybe it was someone else.

Trevor, add an amplifier/inverter for the video, a switchable inverter for the frame sync into the function generator and it sounds like you have a true multi-standard monitor on your hands.

Al

[ppppenguin]

Thanks, Alistair, I think I went that route a few years ago. I don't think I'll try any further. Only thought of him because of using a 'scope for TV display.

[beamcurrent]

A number of scopes had this facility to view a picture built in. The first picture is of a Gould scope specially built for the post office as "Oscilloscope No. 18A"

The image has come out a bit faint in the photo, in real life viewing it is bright and sharp. The scope also has line selection facilities allowing the observation of just one line, or part of the line out of the 625.

I used this scope at the Kempton park radio rally last Sunday to monitor the output of my EMI 201 camera which I had on display at the BATC stand. It was operating on 405 lines to celebrate the 80th anniversary. 

It was so busy I did not get to take a picture of it, but lots of others did!, the second picture is of the EMI 201 (foreground) and the 203 (rear) at an earlier show, again both were operating at 405 lines.

http://www.tvcameramuseum.org/emi/201/201p1.htm

[Terry]

I think Kat Manton has also disappeared from view. She and Jim can both be seen on last photo on this page photo, taken at the NVCF in 2006 when we had a large display of vintage TVs:
http://www.bvws.org.uk/events/photos/200...elevision/

Talking of disappearing, apart from your ill fated attempt to hide from the camera, Jeffrey (!) - can you explain what looks like a headless man with a stick in the centre of the picture?

I wondered if it had been composed of two pictures spliced together but the headless body would have spanned both pictures!