Earlier in this thread:
>>
>> Folks with a better understanding of the reasons for the frequency
>> excursion might offer an explanation. I just vary the vertical wire
>> length to fix and live with the required adjustment.
>>
>> 73, Gary NL7Y
>
> I may not have a better understanding but I lived about 20 miles
> from Gary's qth with a full size quarter wave vertical for 160
> that did the same thing. Adding more radials stopped it and the
> antenna was stable summer and winter. I believe it has nothing
> to do with the trees but ground soil conductivity or lack of
> same.
>
> 73 Rich KL7RA
Thanks for the reply Rich. I agree with the changing ground
conductivity on a seasonal basis, such as ground conductivity is in
Interior Alaska = poor at best I believe. But that doesn't explain
the short-lived phenomenon of resonance shift down and back I saw
during last January's brief above-ground thaw. The ground never
warmed sufficiently to the change conductivity in a few of days, but
the supporting tree apparently did.
It's simply not worth erecting a permanent fix here like you had
nearby. The resonance shift happens with my tree-hugging wire and I
compensate. It took me 5 minutes tonight to go from 1.840 to 1.825
via a longer vertical. If sufficient radials were ground mounted
under a steel tower it may never change for the reasons you noted.
73, Gary NL7Y
>
> _______________________________________________
> 160 meters is a serious band, it should be treated with respect. -
> TF4M
_______________________________________________
160 meters is a serious band, it should be treated with respect. - TF4M
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