[R-390] 6080 in place of 6802 - RMS ???

[Bill Hawkins]

Barry Ornitz (there's several Barry's here),

This group has changed. It isn't like other groups we've
been on where people want to learn, and would be willing
to open a book to do it. They've run off several people
who seemed to know what they were doing, like Dr. Jerry.
Presently we have some really good people who no longer
say anything (like Les, Chuck and Nolan) and some good
people who have adjusted their messages to fit in better,
like Barry Hauser and David Wise.

The way I figure it, these guys ask a question hoping that
someone with Authority will tell them what to do in terms
they can understand, and without looking like they are any
smarter than the guy who asked the question. Nothing wrong
with that, but it does put a damper on learning anything.

I don't expect anyone else to read this, because I've been
put in most people's kill files even though I don't have an
advanced degree. I did see one way of explaining the falsity
of the diode job a while ago:

Take two 6080's and put them in series at 12 VAC. They draw
2.5 amps and the heaters dissipate 30 watts. Now double the
voltage with no diode. They will briefly dissipate 120 watts
(24 VAC x 5 amps). Take a new pair of 6080's and add a 5 amp
diode. The power is cut in half to 60 watts. Wait, this is
twice the rated power of 30 watts for two tubes. Maybe, just
maybe, cutting the power in half with a diode isn't the right
thing to do. We need to cut the 24 volt power by a factor of 4.
I know, use TWO diodes ... but how?

Even if you ignore the math and do it anyway, you are cooking
your R-390 audio deck with 60 watts instead of 30. It could
barely survive 30 watts, judging by the condition of the parts
near the base of the tubes.

If you want to substitute 6080's for 6082's, and if you care
about the survival of your R-390, then wire in a 12 volt 3 amp
transformer for the 6080's.

Regards,
Bill Hawkins