Topband: Ground conductivity
R. David Eagle
kb8nnu at yahoo.com
Tue Mar 29 22:40:39 EDT 2016
I believe that is extremely possible. I have witnessed the same exact thing here in northern lower MI where we live in giant sandbox. I have especially noticed changes in feed point impedance on RX antennas during the winter months when the soils are generally frozen versus the mid summer with lower moisture content.
I have even had this issue with some transmit verticals.....drove me nuts for a while at my last QTH with my 160 inv L where I didn't have a huge radial field.....the feed point impedance would drift between seasons....
One of my next projects is actually going to be setting up a data logger to monitor the soil resistivity throughout the year....Inquiring minds NEED to know!
From: K1FZ-Bruce <k1fz at myfairpoint.net>
To: Topband <topband at contesting.com>
Sent: Tuesday, March 29, 2016 10:16 PM
Subject: Topband: Ground conductivity
Done my yearly spring maintenance of my SE single wire Beverage antenna. With poor soil, It typically is best with a 350 ohm matching transformer and a 330 to 350 ohm termination resistor.
But this year it is best with a 450 ohm matching transformer and 450 ohm termination resistor.
A higher value typically means more conductive soil. I do not have the time, or equipment to make accurate RF ground conductivity measurements now.
But got wondering where Maine gets the WX after it passes over most of the lower 48 states, With climate change and the highest carbon content in the air. Could rain be causing my soil to be more conductive ?.
Has anyone else noticed anything like this ?
PS: Delta,Pennant, Flag antenna notes has a new address www.qsl.net/k1fz/flag_antennas.html
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