[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] writes:
Most 813's had graphite plates, and I never remember
them showing color, I always thought that would be way beyond
what they were good for, or was good for them...if they were glowing!
I was testing my single-813 grounded-grid amp the other day and had it making
500 watts out cw. The plate was a bit red at peak output, but getting very
red fast off the peak of the tuning.
You probably saw a rise in plate current, as well. Off-resonance.
I've had 250TH's in my rig (balanced, cross-neutralized, link-coupled)
and had one show color, while the other did not.
Different brands of tubes.. different plate configurations...
differences all over. but, they still dipped at the same place, and
drew the same amount of current off-resonance, and drew different shades
of red, depending on which tube you look at.
--
73
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