Winter project.

[ppppenguin]

Don't the NBTVA have all sorts of material available? I know you're on their forum.

[Murphyv310]

Hi Jeffrey.
Yes I'm on the NBTV forum but still feeling my way.
I hope to download or obtain some material.
This afternoon I altered the charging cap for the line blocking oscillator just to see if the timebase would run at an even slower rate without too much distress. I have found that I still get results at 1500Hz. the EHT goes down to 3kv though at this speed but decreasing the anode load of the ECL80 triode improves the sawtooth and its peak level, this had brought up the EHT to 5Kv and improved picture shape on 120 lines.
I had been feeding the Aurora from an old B&W camera pointing out of the shed toward the house as its been a nice sunny afternoon and I was quite impressed with the results on 240 & 180 lines, I inadvertently switched to 120 (mechanical) and lo and behold the line lock was reasonable, feeding it with video from a freeview box and its dreadful. I think the reason is the camera was set with the iris at its most closed point so the video level is low. I then tried 96, 90 & 60 and the set will resolve a picture down as far as this.
I'm even more gobsmacked that it's even possible.
I think now I'll need to use the mechanical sync output from the Aurora, I'll need to make a proper clipping circuit, most likely with a 555 timer to give me suitable synch pulses for the line oscillator and possible a divider circuit to trigger the frame. I'll need some form of line phase adjustment to square up the picture and I'd think if I can do this then as far as I can tell the frame should be triggered at the correct time. Of course each standard will require a different divider, nothing that's insurmountable though.

[peter scott]

I came across this little article from Philips Technical Review, November 1936.

http://www.extra.research.philips.com/he...36-321.pdf

Peter

[ppppenguin]

Peter, that's a great article. It's hardly surprising that Philips had a working iconoscope camera in 1936. What's not so well known is that the Baird compnay had built an iconoscope camera too, but it was kept very much under wraps as they didn't have access to the relevant patents.

[Murphyv310]

Brilliant article Peter.
Many thanks for posting.

[peter scott]

Peter, that's a great article. It's hardly surprising that Philips had a working iconoscope camera in 1936. What's not so well known is that the Baird compnay had built an iconoscope camera too, but it was kept very much under wraps as they didn't have access to the relevant patents.

That is interesting! That must have depressed them. Do you have any links to the source of this Jeffrey? The date would be especially interesting.

Peter

[peter scott]

Many thanks for posting.

There are quite few interesting articles in the Philips Technical Review.

See the index here: http://www.extra.research.philips.com/he...Review.xls

and: http://www.extra.research.philips.com/he...echReview/

Peter

[ppppenguin]

Peter, that's a great article. It's hardly surprising that Philips had a working iconoscope camera in 1936. What's not so well known is that the Baird compnay had built an iconoscope camera too, but it was kept very much under wraps as they didn't have access to the relevant patents.

That is interesting! That must have depressed them. Do you have any links to the source of this Jeffrey? The date would be especially interesting.

Peter

I was given the information, including a photo, by Paul Marshall when he was doing his PhD about the origins of British TV. At the time this was in confidence. I would need to check back with Paul before showing the photo. Not sure if it's on public access.

[peter scott]

I had a look at it. The year seems to be 1938. The photo is a little difficult to interpret. At first glance I thought it was a Super "Emitron" but there is no electron lens rotation so I assume the assembly in front of the "Emitron" is simply the optical lens.

Peter

[ppppenguin]

I have that photo in high resolution. Also another of a complete channel with the cased camera sitting on a stand with a bundle of cables going to a CCU.
https://www.scran.ac.uk/database/record....-091-135-C&scache=1l04029tti&searchdb=scran

Other iconoscope related photos here https://www.scran.ac.uk/database/results...CKSEARCH=1&search_term=iconoscope are RCA or EMI.