Topband: elevated radials question

[Grant Saviers]

Don't connect elevated radials to on/in ground radials.

There is a huge ground loss for 4ft high radials on 160m.  7ft is far 
better and 10 ft is pretty good.

There are "W" shaped radial feeds with the base near to the ground but 
IMO it is better to elevate the feedpoint to radial height and add a bit 
of wire to the top load to get back to resonance.

Radials can be a bit shorter than 1/4wl ~ 85% for 4, even shorter for 
more. see antennasbyn6lf.com  Or a single high Q inductor to shorten 
them more, but modeling is needed.

An excellent coax choke is essential for elevated, the 4" K9YC #31 
design is great.

Grant KZ1W

On 10/25/2021 09:03, Greg Davis wrote:
> Hello Topbanders,
> 
> I just got my 160m antenna back up after being off the band for a while,
> just in time for the pre-Stew this past weekend. It is an inverted "J" with
> I'd estimate 90ish feet more-or-less vertical over the tallest tree in my
> back yard. I've got a decent number of on-ground radials laid down from
> previous years, but I plan to add some elevated radials this season.
> 
> There are a few things I'm not sure of. Do I raise the base of the vertical
> to the height of the elevated radials -- 48" inches or so? Do I leave it on
> the ground and slope up from the base of the vertical to reach the elevated
> height a short distance away? Is there any reason not to combine a mix of
> on-ground and elevated radials?
> 
> Thanks in advance.
> 
> 73 de Greg N3ZL
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