Roberts R200.

[Joe]

Last year some time I got a Roberts R200 which didn't work.

   

I changed a few caps but couldn't get it going. I had another look at it a couple of days ago.

I found another electrolytic which was o/c but for all that a 1kc/s signal injected into the volume control would come out of the speaker it wouldn't any further back.

This morning, I started poking about with a diode and amplifier but couldn't get any signals anywhere.

Chiefly because I couldn't think of anything else I took TR1 off and tested it. I was sure I'd tested all three AF117s when I got it and the soldering appeared to have previously been deflowered. Whatever, there was a short between the screen and collector and after bopping that it tested with an hFE of 196 and when it was put back in the set that worked.

I also checked the IF alignment which was a bit out and a quick twiddle improved things even more.

Cosmetically it's had a clean up and a new piece of leather fitted to the outside of the handle.

   

It's an achievement for me as I think it's the first transistor set I've managed to repair that's needed more doing than bad connections or something equally obvious sorting out.

This is as well as I've just bought a Hacker Sovereign - more on which when I get it.

- Joe

[Mark R]

Nice one young Joe, I love it when a plan comes together.

cheers Mark

[tiv48]

i think it each to there own until the last 5 years most of what i have repared apart from my own hifi stuff has been solid state, i thought i had left vaves behind in the 70's my interest was rekindled be cause i got to be known as someone who repair vintage electronics that others said could not be done .trouble is i had to make a living, now im no longer in the trade its nice to pass on my experiance with things that used to be run of the mill.
now i do it for enjoyment and prefer valves
rob t

[ed731pdh]

I have an old Roberts 404 that was dead as a dodo, no arguments, changed out every AF117 to restore operation. The one in the IF can was a stinker, too much heat and the foil track lifts.

[Joe]

Yes, I'd previously tried and failled to fix an R600. That is now the bench amplifier.

   

Maybe it was the sight of that that made scarred the R200 into behaving.

- Joe

[Tedzed1]

That looks really nice now Joe, was it a case of an A117 and the "tin whisker" syndrome?

[Joe]

It must have been as a belt from a charged capacitor cleared the short.

- Joe

[Andrewausfa]

These are nice looking radios, well done on getting it working Joe. I bought three R600s one of which I got working but the other two I gave up on after trying to take apart a Mullard module!

Andrew