[TenTec] Vertical Antennas (was Radials)

[Ron Feutz]

Jim,

My 160 array at the new QTH is two inverted L's with about 55' vertical 
spaced 1/4 wave and fed with the 90 degree ports of a Comtek 4 square 
controller for a switchable cardioid pattern.  On-air results mirror the 
modeling from ON4UN's book.  F/B is anywhere from 1 to 2+ S units, 
depending on the arrival angle of the incoming signal.  The model shows a 
very broad front lobe, with the 3 db points at 176 degrees, and results 
confirm that.  I pointed mine so that the "nulls" did not effect any 
significant DX areas.  Pointed east, it covers northern EU to South 
America/Caribbean.   Pointed west, it covers everything else (from central 
WI).  The "nulls" are not really null.  In my case, the southern null 
points at west MS, east TX, and I work everyone who is on there in the 
contests.  Signal strengths are equal in the "nulls", regardless of which 
way the array is pointed.  All in all, a very effective array for both TX 
and, thanks to the F/B, for RX as well.  Definitely for the low bands, 
phased vertical arrays are the way to go if you have the room.  There are 
cheaper ways to feed it - I had the Comtek box from a 4-sq at the previous 
QTH.  Get ON4UN's book for a wealth of info on all types of phased arrays.

73,

Ron - WA9IRV


At 11:10 AM 6/9/2004 -0600, you wrote:
>Guys,
>
>Does anyone here have any experienced with vertical phased arrays?