HMMMMM!!!!!!!!
If that is the case, WHY do the pro broadcasters install all 120 radials at
full length; even bare wire buried a couple of inches underground?
Inquiring minds want to know where this conversation is going.
I understand that when you are doing radials, with a few they are part of
the resonance factor for the vertical.
However, after a dozen or so radials are installed the length does NOT
necessarily determine resonance as the FIELD of "radials" becomes a
composite Ground Plane.
Bigger Ground Planes are Better!!!!!! Think salt water.
So, IMHO, the 1/4 WL radius from the vertical is most likely at the break
point for "return vs cost". And the more Ground Plane you can place in that
1/2 WL diameter circle, the more efficient your vertical will be.
If I was installing insulated "radials" I would make them full 1/4 WL
regardless of the VF. It just makes good engineering sense.
I am still learning, so if I am incorrect in any of these items please
enlighten me.
Mis dos centavos.
73 de Milt, N5IA
-----Original Message-----
From: Eddy Swynar
Sent: Friday, February 10, 2012 9:48 AM
To: herbs@vitelcom.net
Cc: topband@contesting.com
Subject: Re: Topband: Radials help
On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote:
> One advantage of using insulate wire is that the velocity factor of the
> wire
> on ground or (ROG) allows for shorter lengths. This is important if you
> have limited yard space.
Hi Herb,
Interesting point...!
According to either the ARRL "ANTENNA HANDBOOK", or ON4UN's "LOW-BAND DX
HANDBOOK", the velocity factor of insulated wire placed atop the ground is
50%...
I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the
ELECTRICAL equivalency of a wire radial that is 1/4-wave long...
Maybe THAT'S the reason why I employ a total of 24 insulated radial wires,
65' long (each) beneath my "L" elements...it may not be an "exact science",
but hope springs eternal...! (Besides, have you seen the price of copper
wire lately...?!). : >)
~73~ de Eddy VE3CUI - VE3XZ
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