Hasan,

If you download program ENDFEED and insert details of your antenna and
ground radials system, you will find the impedances closely agee with
what you actually get. (I'm always very happy when this happens.)

Enter the exact 80-meter band frequency at which you have found your
own antenna to be 1/4-wave resonant. Then slightly prune antenna
height until the program says the antenna is 1/4-wavelength long. Very
likely your antenna horizontal section is sloping.

As a final check, do with the program what you have done with your own
antenna, and subtract the RF ground resistance from the antenna input
resistance to give the radiation resistance. (The radiation
resistance is not displayed by the program although, obviously, it is
used internally.)

The primary purpose of the program is to calculate the L and C values
of three different impedance-matching networks (tuners), which you may
find useful. Radiating efficiency is also calculated and displayed.

Download ENDFEED, an old program of mine, from website below.
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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