[Amps] SB-220 parasitic suppressors

[R.Measures]

On Nov 4, 2004, at 12:15 AM, Steve Thompson wrote:

> Tony King wrote:
>> At 01:21 AM 11/4/2004, R.Measures wrote:
>>> <snip>
>>> A GS-35b has 0.12pF of anode-cathode feedback C.  An 8877 has 0.10pF
>>> of it, so they have a fairly similar amount of internal feedback.
>>> Our 8877 low VHF-Q parasitic suppressor retrofit kit has both an
>>> anode suppressor and a cathode suppressor.  It comes with a money
>>> back guarantee.  So far, the only refund has been to a guy who said
>>> he did not know how to solder. --  Today's trivia question:  At its
>>> max freq of 1000MHz, what is the reactance in ohms of the
>>> output/input feedback path in a (g-g) GS-35b?
>>
>> Very interesting.  My guess: 1326
> Feedback C on the data sheet is almost certainly measured at low 
> frequency.
> The feedback characteristics at V/UHF might be different.

Not for any reason I can see.  The dielectric is a vacuum, not an 
organic compound.
>
> By now there's lots of amps out there using the Russian planar 
> triodes. Has
> anyone heard of any problems?

Richard L. Measures, AG6K, 805.386.3734.  www.somis.org