>> It's just another kind of balanced bridge, so it should improve
>> stability at the VHF resonant frequency too, provided that phase-
>> inverting transformer is sufficiently broadband. More specifically, it
>> won't make VHF stability worse than the un-neutralized condition
>> unless the phase of the feedback has somehow reversed itself between
>> 30MHz and 80MHz (which is easy enough to ensure).
>I'd make sure I had a neutralizing system, and use a suppressor
>like the Ameritron AL811H uses if I was refurbishing a Warrior.
>There are two distinctly different stability problems with tubes like
>811's and 572's.
>One is the high feedthrough capacitance that makes such tubes
>unstable at upper HF. ...
// I have never heard of a grounded-grid 811A or 572B oscillating at
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
FAQ on WWW: http://www.contesting.com/FAQ/amps
Administrative requests: amps-REQUEST@contesting.com