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Old November 8th 05, 04:34 PM
Tam/WB2TT
 
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Default MFJ-269 Antenna/SWR/RF Analyzer


"Roy Lewallen" wrote in message
...
Tam/WB2TT wrote:

I will have to try your configuration. I did C - L - C/2 - L -C, with
C=1000PF, L=2.2uH. According to SWCad, the gain is flat above 2 MHz, but
there is 120 degrees phase shift at 4 MHz, relative to the phase at 100
MHz.


The center component should be 2C, or 2000 pF for your experiment, not
C/2. The circuit is simply two pi networks in cascade, each having all
component reactances equal to the "transmission line" Z0. Each pi section
mimics a quarter wave transmission line.

Roy Lewallen, W7EL

Roy,
I wasn't too clear, but I have 2 T networks back/back. That makes the center
cap C/2. I am going to run SWCad on the Pi configuration later, and see what
that does.

Tam/WB2TT