>
>Hi all,
>
>I designed a switchble input pi-net for my 'two-holer' (a pair of 8877's).
>The
>calculated Z is aprox. 23 ohms. The circuit is located close to both input
>blocking caps and tubes. I tested this circuit with both tubes connected to
>the sockets and a 23 ohms resistor cross to both blocking caps. I tuned this
>pi-net for all bands. As source generator I used the MFJ Antenna Analyser
>259.
>All settings was nearly SWR 1:1 and I was satified. Later, under real power
>conditions all values are away up to 2:1 and higher.
? The best load is the real one.
>I know my first test was
>made under static circumstance and in the real world it works under dynamic
>conditions. But I do have no chance to tune the network under operation
>conditions (no possibilities).
>Is there to go another way to fix it right under 'could conditions'?
>Otherwise
>I have to make a new metal design to operate the input pi-net parts under
>power conditions.
>Maybe it would be better to test this circuit with more r.f. power than the
>MFJ 259 produces???
? The cathode Z of a GG amplifier is unlike a resistor.
- cheers, Werner
>
>
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>
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
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