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Old January 12th 07, 06:00 PM posted to rec.radio.amateur.antenna
André André is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 11
Default GPA vs Vert dipole

Hello,

(pse excuse my english)

I have some questions about GPA and vertical dipole
(vertical quarter wave with four horizontal radials and half wave center
feed vertical)

With a modelling software (MMANA) and antennas calculated in free space
conditions, at resonance,I get 72 Ohms for the dipole (correct), but only 22
Ohms for the GPA as I expected 36;

does anybody know the reason ?


Another question, The radiation patterns seem to be identical for both
antennas, so I expected the same gain with GPA or dipole, but the soft give
2.13 dBi for the dipole (correct) but only 1.57 dBi for the GPA.

Not due to the fact that the currents are greater in the GPA, as the soft
was working in 'no loss' conditions for the wires.

Tnx if you have solutions,

73

André
F5AD
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http://f5ad.free.fr/