>
>
>
>> >
>> >Hi Rich,
>> >
>>
>> >
>> >On many rigs the RF out control is too close to other controls and could
>> be
>> >easily bumped into the "gee, I wonder what vaporized the grids in my $400
>> >8874's?" position.
>> >
>> Autopsy shows that the 8874 grid is not damaged by overdrive. The damage
>> is to the cathode's emissive coating - which flakes and shorts the grid
>> /photo of flaked cathode in "Parasitics Revisited", Sept/Oct 1990
>> *QST*./
> [Steve Katz] Well, whatever! I only know the cost of 8874's
>currently sucks and it doesn't seem to be decreasing, so short of replacing
>them with something else (a serious possibility), I try to take care of
>them...have had one set in one amp for 15 years and still working fine.
// Taking care means don't exceed 350mA of I-anode per bottle in AØ
mode.
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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