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Old January 23rd 11, 11:05 PM posted to rec.radio.amateur.antenna
John - KD5YI[_3_] John - KD5YI[_3_] is offline
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First recorded activity by RadioBanter: Dec 2010
Posts: 54
Default Math help characterizing Antenna, Please

On 1/23/2011 11:10 AM, amdx wrote:
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


I cheated. I used a Smith chart.

It is 170 - j530.

Cheers,
John