Richard, Thierry and the original poster I repeat:

The R7 is NOT a quarter wave vertical -- it is a half wave end
fed antenna.

A quarter wave radiator needs a ground plane or radials to work against for
sure -- but Cushcraft sez a half wave antenna doesn't need radials as it is
like a horizontal dipole turned vertical and end fed (high impedance) rather
than center fed.

I suggest you read and study the following:

The Cushcraft manual it explicitly states "The
R7 should not be attached to a ground radial system".
URL: http://www.cushcraft.com/support/pdf/r7.pdf

Do you know what is in the black box matching unit ?? If not see URL:
http://www.iol.ie/~bravo/r7_vertical.htm

A local Ham added radials -- couldn't tune the antenna -- so he added a
tuner. When he ran a kilowatt into this mishmash -- the black box blew up.
So he repaired it as in URL:
http://www.iol.ie/~bravo/r7_vertical.htm

He no longer has the added radials and tuner and runs a KW all the time with
no ill effects -- let the experimenter beware.

I know this is a controversial subject -- rehashed many times here, mostly
because folks treat the R7 like a quarter wave vertical -- which it isn't
and the R7 has that complex matching black box design which I wouldn't mess
with by adding radials. Unless I had the proper test equipment and expertise
to determine what effect added radials have on the impedances and matching.
Cushcraft undoubtedly did this.

More at URL:
http://lists.contesting.com/archives.../msg00059.html

AND http://dayton.akorn.net/pipermail/to...ch/037180.html

Regarding decoupling the feed line -- Cushcraft recommends an RF choke 8
inches in diameter and ten turns on the coax.

Me -- I trusted Cushcraft and followed their instructions. Been working
great for 6 years now.
I won't run out the brag tape on countries worked with it -- means nothing.
--
From one currently in the Cloaked Mode

Any clod can have the facts, but having opinions is an Art.
Charles McCabe (1856 - ), San Francisco Chronicle






"Richard Clark" wrote in message
...
On Wed, 19 May 2004 16:40:05 -0700, "Just Another Opinion"
wrote:

Well Thierry your advice is good for a 1/4 wave vertical -- but not a
half
wave end vertical.

There is absolutely nothing wrong with Thierry's advise. As the
subject of radials/counterpoise/ground is often either over engineered
or under engineered (often to no apparent difference to the distant
contact). It may complicate the tune, but it may also bring reward.

Lookup the theory and you will see why.

http://www.njqrp.org/n2cxantennas/halfer/

Hi OM,

If someone wants to invest in the treatment that Thierry suggests,
there is no down-side - this "theory" notwithstanding (which, by the
way makes no effort to prohibit it, to its credit). Multiple radials
also serve to decouple the feed line which then provides a more robust
reference against which the antenna operates.

73's
Richard Clark, KB7QHC