[TowerTalk] AA-200 numbers

Vytenis Sciucka vytenis.sciucka at gmail.com
Tue Feb 3 03:55:38 EST 2009


Hi guys,

Last November I loaned AA-200 antenna analyzer to look at my 1/4wl
vertical performance. Antenna is HyGain AV-18HTJR and has 24 ground
radials of different length (0,1-0,25wl for 7MHz). SWR shown did not
surprized me. It is about 1.6:1, but I'm confused to interprete all
remaining numbers:
Fq = 7,000 MHz - well, this does not need explanation
SWR = 1,69 - this one also
Return loss = 11,85 dB
Z = 78 - j16 Ohm
|Z| = 80 Ohm
C = 1394 pF
Zpar= 82 - j399 Ohm
Cpar = 56 pF
Len(1/4) = 7,07 m,
Len(1/2) = 14,14 m
Can someone explain me please which numbers are most important. Does
it mean I have to use 56pF capacitor to have most out of antenna on
this band? Analyzer manual is very short about these numbers. I will
also appreciate if you point me any link that has these descriptions.
Antenna is very close to metal/concrete object (~30cm proximity) and
apparently this affects swr and other numbers. I'm waiting for better
spring weather to move it to more open place.

Thank you

Vytenis
ly2kz


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