----- Original Message -----
From: "Sean H. Breheny" <shb7@CORNELL.EDU>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, February 20, 2003 1:18 PM
Subject: Re: Re. [EE]: Looking for good ref for antenna grounding?


> Hi Ling and Michael,
>
> I'm flattered to be included in the list of "RF experts" ;-) (Of
course,
> assuming I'm the Sean you are talking about!)
>
> I have to admit that I have no direct experience with large HF
vertical
> antennas (which, as Michael did, I assume you are talking about).
However,
> from what I do know, I like Michael's suggestions: either make your
radials
> more robust or use an antenna type that doesn't require them.

AFAIK, theres really not much else that he could do.  ;-)

> What kind of soil do you have on this island? It might also be
possible to
> just place the radials in the ground, but probably not if it is sandy.

AIUI, the radials don't actually have to be in contact with earth ground
to still function well.  He could spiral the radials around so that they
are not so far into the sea and this should work nearly as well, as the
electrical length of the radials would still be the same.  He may have
to tweak the matching to the antenna though, since nearly anything that
he does will have some effect on the feedpoint impedance and possibly
the radiation pattern.  I'm a bit rusty on my antenna theory, as I'm
sure you can see.

michael

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu