? The best bias V for the 8877 is that which produces the recommended
ZSAC of 90 - 180 mA.
In other words, it is not very critical.
That is true, but I have found by testing >30 new 8877's @ 4 kv
key-down, that 12 volts of bias succeeded in holding the ZSAC
below 180 ma in every case. A trait of this tube is that it seems
to shift into "overdrive" @ c. 3850 volts key-down. (less drive
required, and better efficiency) Increasing the anode voltage
from 2500 to 4000 volts results in in about a 30% increase in
power output with 5% less drive.
Just an observation by this old codger over the years.
(((73)))
Phil, K5PC
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