On Friday, April 4, 2014 8:39:52 AM UTC-5, Wimpie wrote:



For zero elevation (relevant for line of sight comms in VHF and up),

the gain will virtually not improve when using horizontal 3/4 WL

radials. The horizontal radials don't contribute to the vertically

polarized wave.

Horizontal no.. Try them sloping. As far as I know, the only
case where horizontal radials are preferred would be with the
5/8 radiator with 1/4 radials. In that case, they are better
straight out than sloping. But if I remember right, all other
cases will be better with sloping radials.




And for an even better pattern use sloping 5/8 WL radials, which

will start approaching the gain of a dual 5/8 WL collinear.



Agree, that really helps! You have to take care of mast/feeder

radiation that may distort the pattern (hence gain) significantly.

Sure. But one should do that with any elevated vertical for the
best performance.





I've compared 1/4 wave GP's, 1/2 wave's with decoupling, and

5/8 GP's with 3/4 and 5/8 radials on 10m to distant local

stations, which is a good test of low angle performance.



The 5/8 was always the best antenna in the real world using

low angle space wave paths 30-40 miles across town.



Probably this was because of the added heigth for the 5/8 lambda

radiator over a half or quarter wave, or you had (somewhat) sloping

5/8 WL radials.

They were sloping. But... I remember that I started out with
a 5/8 with 1/4 radials. It was also better than the 1/2 wave even
with the theoretical problems.. It could have been due to the higher
radiator, but not sure.. I'm not sure if an extra 5 feet in height
would make that big a difference on a 30 mile local path when the
base was a fixed 36 feet high in all cases. Could be, with the current
distribution of the usual 5/8 wave element.