From august 99 to today I measured the enviromental loss resistance of my
antenna. The measurments were done by measuring the TX output power and the
antennacurrent. The known coil losses were subtracted.
Results (all values in Ohms) :
17 Aug 99 : 130 31 Aug 99 : 126
16 Sep 99 : 128
01 Oct 99 : 127 17 Oct 99 : 122
11 Nov 99 : 118 30 Nov 99 : 113
16 Dec 99 : 110 30 Dec 99 : 108
14 Jan 00 : 110 29 Jan 00 : 114
15 Feb 00 : 110 28 Feb 00 : 116
13 Mar 00 : 112 28 Mar 00 : 128
14 Apr 00 : 138 25 Apr 00 : 135
From this data it seems that periods of dry / wet weather have a rather
limited effect on the loss (about 5 to 10 Ohms) while the seazonal effect
(summer / winter) seems to be in the order of 25 to 30 Ohms.
In the past I have measured values as high as 155 Ohms (dry period in
summer) and as low as 105 Ohms (wet period in winter).
The major summer / winter effect can be explained by the high ammount of
'greenery' around the antenna.
73, Rik ON7YD
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