Russian CRT

[Murphyv310]

Hi.
Indeed it can be. These are from a few years back. 180, 240, 405, 626 & 819 lines. Also 525/30 & 441/30
The poor linearity is due to the scope on AC on some pictures switching the input to DC cures the issue.

[Radio Fixer]

Theres some good results there Trevor.  Saw 1967 on one of the test cards so going back a long time.  Maybe there was a fashion going on to put TV pics on 'scopes?

Can you remember how it was done.  Guess someone will do it with an Andinuo when they run out of other ideas to use one for  

Thanks Gary

[Murphyv310]

Its quite easy.
On my Hitachi scope you need a negative going video input and about 5v p-p drive to the Z mod, one BC109 as an amp which reverses phase (common emitter) does trick, a 555 timer as sawtooth oscillator and a 1551 chip as a frame sync separator to lock the 555 timer. It does all frame speeds perfectly. The frame output is fed to the X input switched to DC and the scopes timebase takes care of the line scan, works a treat.
It's better with other scopes that don't have the graticule embedded in the CRT and have better focusing. My trusty Tek scope blew up a few years ago and is beyond repair.

[Radio Fixer]

Thanks Trevor

What is a 1551 chip: got confused looking online.

Guess harder when I was at Mullards as they had to do it with valves.

Gary

[ppppenguin]

I think Trevor means an LM1881 sync separator.

[Murphyv310]

Sorry.
I was working indoors and 1551 came to mind Jeffrey's correct.

[Radio Fixer]

The birth of the chip was really something wasnt it. I used the first RTL ones (Fairchild?)and some of the gates only had a few transistors in them. The JK flip flop was a bit more complex though.

These were in round metal cans, maybe 1/2" diam with legs sticking out the bottom. The Industrial Eng guys made up a forming machine that bent the legs to fit in spaced PCB pads.

Somewhere I have a Data Sheet, just a few pages for the limited number of devices that were available. If I find it I will post a few pics.

Interesting discussion, thanks Gary

[peter scott]

Peter obviously worked for the sort of company where spectrum analysers were readily available

True, and we also designed/built selective level measuring sets (a spectrum analyser without the pictorial display).

Peter

[Radio Fixer]

OK.  A look into the past.  When logic chips or cans had circuit diagrams.  How quaint it seems now but at the time it was thought magic.

But then came Cmos and TTL and Wow!  LS TTL.  Could really do things with that, speed and low power.

   
   
   

Gary