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Old 07-14-2010, 04:33 PM
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VintagePC VintagePC is offline
Tube bug got me 05/2010
 
Join Date: May 2010
Posts: 535
Well, I've ended up replacing just about every resistor in the set (save 5 or 6). The tube voltages around the 6AQ5 seem to be better now (at 12V in radio mode), but there's still some weird stuff going on around the 6AU6... I get about 30V on pin 5, and 20V on pin 6. This does change when I adkust the volume knob. However, the 1.1V line is now at about 0.9V, much better than originally.

Also, the tubes in the radio part are way out;
There's 89V on the 6BE6. (I think the schematic says 85) and there's well over 40 on the 6DC8. Could be okay if the schematic shows 56, but it looks more like a 36 to me. Haven't tried to tune anything.

There are also a multitude of disc caps and resistors attached to the volume knob, of which I can't find any trace on the schematic. I haven't checked those yet. A wild guess says they may be to filter interference, but I don't know. Pics available on request.

The set's probably been too damp, as these are carbon composite resistors.

I should also note that the replacements are all salvaged resistors, and while I've checked them to make sure they're within 10%, I have no idea how they behave under load.

I'm inclined to go and buy new ones and just replace all of them for this reason, and also because the leads on these are much shorter than what was in the set; so I've had to do some clipping and solder to the old leads... which doesn't look pretty, but it works in a pinch.

Reese- hope you have some advice (even if it's just to go buy new resistors) since Electroking is away for a few days
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