[AMPS] Input pi-net

[Tom Rauch]

You have to be careful using ahigh pass network, or a network that 
does not hold the cathode at a low impedance for high order 
harmonics.

Under some conditions, that will seriously hurt both IMD 
performance  and efficiency.

> I now use a "T" match on the input. This idea was "stolen" from
> Creative  Electronics. I simply install an MFJ antenna tuner ($59.95) near
> the tubes. For two 8877's, I use a 2:1 unun transformer between the tuner
> and the cathodes like Alpha did on their 77SX. This allows a perfect  1:1
> input VSWR on ANY frequency between 1`.8 and 30 mhz and works every time!

73, Tom W8JI
w8ji@contesting.com

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