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Heathkit IO-12

PostPosted: Thu Oct 11, 2012 10:57 am
by Ty_Bower
Is there any value in an old Heathkit IO-12 'scope? It does power on and makes a focused horizontal trace. I had no probes or signal source with me, so I couldn't test it any further. Price is $20... maybe the tubes inside are worth that much? It's such a charming old thing, I'd hate to just gut it. Maybe I shouldn't go back to the thrift shop tonight. Sigh.

Image

PostPosted: Thu Oct 11, 2012 12:34 pm
by Geek
Is the transformer good? (plug it in and no smoke and flames?) If it is, it can be used for audio. But expect to recap it at the very least.

If it were me, I'd buy it, pull the tubes, CRT and knobs (which can likely be ebayed for your money back + a coffee) and send the rest to recycling ;)

Cheers!

PostPosted: Thu Oct 11, 2012 6:56 pm
by EWBrown
For $20, it is well worth it. There are numerous useful tubes, pots, etc, and of course, the power tranny is good for modest-powered tube amp projects, I wouldn't use it for much more than a mono PP or stereo EL84 or 6V6 SE amp. It definitely would not be even close to sufficient for PP 6L6GCs or EL84s...

It is very likely that you will find that most of the tubes inside are Mullard or Telefunken, as these were considered as being "cheap imports" back in the 1960s.

The power trannie is approx 350-0-350 @ 60-70 mA, 6.3VAC @ 3-4 A and a 600-1200 VAC @ a few mA for the CRT HV, this includes a series-connected HV filament winding for the 1V2 (typically) HV rectifier tube. Just cut those leads short, and cap them off with heat-shrink tubing to prevent any unwanted HV arcing, minor corona discharge, etc.

I gutted out one of these same scopes a few years ago, the CRT worked, but had a burned-in dark trace across the face, and a couple of the PSU electrolytics were leaking out their contents =:o

I'd have to dig deep through the boxes in the cellar to find it, but I think I still have a manual for these scopes.

/ed B

PostPosted: Tue Oct 16, 2012 10:30 am
by Martin
-If you don`t want to use and to restore the old scope, let it go to a person who like it.

To me it would be a shame to part out an old radio, amp or test gear.
But when I must read like that in all audio related communitys the day will come I part out my Marantz Tuner and build a horrible looking homebrew scope from the rest O:)

greetings
Martin