>My Home brew 4-1000 amplifier works great except for on thing. The power out
>seems low. I believe it may have something to do with the low idling
>Plate voltage is 4,600 VDC and idling current is about 80 ma.
Zero signal anode current - a.k.a. idling current - should be about 20%
of max.., or around 150mA.
>The max plate
>current I can load it to is 450 - 500 ma. At 4,200 VDC under load and 450 ma
>plate current, gets 1,450 watts out with about 130 watts drive.
Normal drive power is around 190w with such low anode V. If you want to
make an 8166/4-1000A play well with low drive levels, you need 6 to 7kV
on the anode.
>the B- line for stray resistance; none. Have tried it with the zener both in
>and out; no difference.
If the zener in and out makes no difference, the zener may be shorted.
>Power supply is capable of more than enough current
>and I have 200 watts available. I have 3 tubes: all 3 operate the same in my
>amplifier, full output in another amp.
If you want to realize the full capability of the 8166, you need to drive
it to about 750mA, Bob. Grid-driven, 100w will do it, however, in
grounded-grid, it takes about double that.
R. L. Measures, 805-386-3734, AG6K
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