[TowerTalk] K8UR wire 4-SQR characteristics vs 1/4 vertical array design from N0AH

[Pete Smith]

At 01:19 PM 8/9/00 -0400, Dick Green wrote:
...
>All in all, I'd say that if you will have an easier time putting up 65' of
>tower than constructing radials, and don't mind climbing, the dipole array
>is the way to go. No doubt, it can be constructed *much* faster and there
>appears to be no performance penalty.

Actually, it's easier than that, even.  My 80-meter dipole array is hung
from my one-and-only tower, with yagis on top.  I set up two blocks near
the top with dacron rope halyards, and run the tops of 2 of the dipoles off
each halyard.  That way, if anything fails (and it has) I can lower the
entire pair of dipoles to repair whatever is required.  In my case, I'm
using the 4-dipole array parasitic style, with ~155 degrees of feedline
length providing the loading at the center of each of the unused dipoles.
I have no way to measure gain, but F/B is invariably 4 s-units (whatever
that means) or better, and on some high angle signals (like stateside QRM)
switching the back of the array toward them drops the signal from S-9 plus
to S-2 .  First time it happened, I thought a relay had hung up...  It's
definitely competitive with the 4-squares I've tested against, but down an
S-unit or so to K3ZO's KLM yagi...

Modeling shows no need for radials, and good directivity extends all the
way from 3.5 to 3.85 mHz.  Advantages are simplicity and no dumped power at
all, though you do have to homebrew the switchbox.

73, Pete Smith N4ZR

The World Contest Station Database 
is back up and running at
http://www.qsl.net/n4zr 



--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com