Dear Mikek (no call sign):

Assuming that the inductor is 3 +j310 because it must have some loss and
calling the capacitor -j717, my trusty calculator estimates the antenna
looks like 159 -j526. The real part seems high - probably due to ground
losses.

However, the idea that even such a simple an antenna can be modeled as an R
and C over the AM broadcast frequency range seems unlikely.

An instrument such as the AIM4170C would provide Z with greater confidence
and do so at each frequency of interest. However, in the broadcast band it
is not clear that such a set of impedances can be used for something useful.
What is the actual goal?

Regards, Mac

"amdx" wrote in message ...

I put up a long wire antenna, it is an inverted C.
The antenna is resonant at 3.55 Mhz.
I want to characterize it an the AM broadcast band.
I have made a measurement at 500 Khz and I had to install a parallel
capacitor
to get my variable inductor to bring phase to zero.
I don't know how to do the math to find the impedance of the antenna
with the L and C in the circuit.
Can someone look at my drawing and give me the math so I can figure out
the impedance. Then I can get the numbers at other frequencies for the band
and calculate those impedances.
See drawing here. I want to calculate the Unknown Impedance.
I need the R and the C of the antenna.
http://i395.photobucket.com/albums/p...naat500Khz.jpg

Thank you, Mikek


J. C. Mc Laughlin
Michigan U.S.A.
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