From expeerience with VHF leaves do play with the RF in the air, some of
the locals believe that the leaves when close to the antenna can form
another layer, eg a canopy. Also, I have read that some of the antennas
with terminating resistors work better if a wire is placed between the
resistor and the ground at the feed, makes better contact a probably a loop.
Chris opr VE7HCB
At 11:33 AM 2001-10-21 +0000, alsopb wrote:
>I'm beginning to think that leaves on the trees is adversly affecting
>the directivity of my beverages.. or the phase of the moon or...?
>All 7 of them don't seem to show the directivity on 160/80 that they
>did last winter.
>Two are two wire beverages (one of the pair unterminated, the other
>terminated to ground) and three are single wire with resistive
>terminations. All 7 seem to suffer from the same directivity loss.
>I've checked all joints, switching paths and even measured the
>terminating resistor values (at DC of course). The Z values as
>measured on an Autek RF-1 on either side of the transformers agrees
>well with last year.
>The one thing I can't readily check is the ground side performance.
>I'm wondering if it is just too early in the season to expect them to
>perform or because they are run under a canopy of trees which still
>73 de Brian/K3KO
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FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Administrative requests: towertalk-REQUEST@contesting.com