> The 30L-1 does not have neutralized tubes, so apparently 811A'a do not
> absolutely require it.
If the 30L1 had neutralization, Collins would not have to have a
series of stability modifications to that amp. The amp also would
be stable if the load was removed from the input and output, which
it is not (as produced).
They also would not have to tell people to use a certain length line
between the exciter and PA.
ALL four 811A amplifiers need neutralized above 20 MHz for
stability when operated at normal voltages. The only exception
would be if there somehow was some "accidental" feedback added
to cancel feedthrough inside the tubes.
73, Tom W8JI
w8ji@contesting.com
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