In a message dated 2/6/99 8:40:53 AM Eastern Standard Time, kq8rp@primenet.com
writes:
<< So straighten me out? Why am I seeing 1400 to 1500 at the
beginning and
then it falls back with two tubes? But with one tube it stays pretty
constant at 1100? >>
More description needed about amp arrangement.
Some possible culprits: Ferrite coils involved, ferrite saturates at higher
power, heats up and loses its properties, coil "dries" up. Same goes for
ferrite filament chokes (had that happen on 160).
Another source of problem is drifting ceramic padding capacitors, they heat
up, change value and proper values drift and detune the circuit. Usually can
be compensated "tracked" by variable at the output.
Basically something is "eating" up RF or detuning the circuits.
73 Yuri K3BU, VE3BMV
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