[TowerTalk] Th6dxx swr

[Jim Lux]

-----Original Message-----
>From: Lee Buller <k0wa at swbell.net>
>Sent: Oct 15, 2008 9:55 AM
>To: Bob Ortasic <rortasic at neo.rr.com>, TowerTalk Reflector <towertalk at contesting.com>
>Subject: Re: [TowerTalk] Th6dxx swr
>
>Bob,
>
>I set the ones I have used for mid-band.  That gave me the best band coverage on 20-15-10.  Make sure you waterproof the traps.  The balun should be good.  
>
>That low to the ground you will not get a good reading.  As the other feller said....stand it up on the reflector vertically.  Watch out for overhead wires.
>
>Lee - K0WA
>


I did some NEC4 modeling of the effects..
See http://home.earthlink.net/~w6rmk/antenna/yagiht.htm

Resonant frequencies change by about 100kHz for a 20m 3 element yagi, comparing between 70ft and 6ft off the ground.  Pointing it up helps, soil properties also change the effect.

Jim, W6RMK