Sciaky model C.R.O.I. what is it?

[(*steve*)]

Here's my latest find for restoration. It looked interesting, but I don't know anything about it.



It's 15.5 x 11.5 cm (x 11.5cm deep).

Probably made in Australia. Capacitors are a mix of British and Australian made. Contains 2 x 6AM6 tubes and the display tube (so far unidentified). No obvious rectifier...

Has someone snapped off banana plugs in the sockets?

What the heck does it do?

[tggzzz]

My guess is that it is a small, special purpose "cathode ray oscilloscope indicator".

[james_s]

It's obviously an oscilloscope, a rather primitive one though I'd say.

[(*steve*)]

I guess the tiny display tripped me up.  It's the size of a magic eye tube.  I can't imagine I'll see a lot of detail :-)

Maybe there's some selenium rectifiers hidden inside it.

[Gyro]

That looks pretty old! That Art Deco decoration around the CRT makes me think early '30s [EDIT: Although 6AM6s would make it late '40s, somebody had a taste for retro!]. When did Australia get 240V AC mains?

It looks like an interesting restoration project - internal photos would be nice!

If you do manage to get it working, I wouldn't trust the transformer Primary - Secondary insulation to be up to scratch. I would run it off an isolation transformer - to protect the transformer as much as anything. Yes, be prepared for Selenium, probably including the CRT anode supply! (look for a narrow srbp tube).

[chris_leyson]

It's probably from the 1930s'. Frequency control would set the time base speed and the sync control would be adjusted to get the time base to synchronize or lock to the Y signal, if out of lock the time base would still run just like the auto setting. Before Tektronix invented the triggered time base, injection locked oscillators were used to generate the sweep and the sync control adjusted the amount of injected signal.

[james_s]

That looks pretty old! That Art Deco decoration around the CRT makes me think early '30s [EDIT: Although 6AM6s would make it late '40s, somebody had a taste for retro!]. When did Australia get 240V AC mains?

It looks like an interesting restoration project - internal photos would be nice!

If you do manage to get it working, I wouldn't trust the transformer Primary - Secondary insulation to be up to scratch. I would run it off an isolation transformer - to protect the transformer as much as anything. Yes, be prepared for Selenium, probably including the CRT anode supply! (look for a narrow srbp tube).

I dunno, I have a 1937 Philco console radio that I use regularly, never occurred to me to worry about the power transformer. Lots of other people running antique radios and other gear without transformer problems. I'd definitely replace any wax or electrolytic capacitors though.