Mis tres centavos:
I think you are right on!
There is confusion what is radial - as part of resonant antenna radiator vs.
ground (plane)
One has to look at the current distribution curves in EZNEC and se what current
is in what, what is radiating and what is "eaten" up by the loses.
One thing is, for the antenna hardware to form the radiation pattern.
Another thing is contribution of the ground (plane) to forming that pattern
(reflections, interaction). Oh, and the polarization "thing".
Mis quatro centavos:
The best vertical monopole? 3/8 wave radiator, with 1/8 one (for some
horizontal component) or two (for max vertical pol.) elevated radials over salt
water mud or the biggest mother of ground screen/radials you can get.
You will get most efficient radiator with most efficient "mirror" for most of
RF down to the horizon.
Proven by those on salty marshes, K6SE/K6ND stint from the Salt Lake, W8LRL
with 360 radials 200 ft long, Team Vertical beach adventures, W3YOF, et al.
(worth about 10 - 15 dB)
Mis cinco centavo:
Took me some 45 years to realize what makes antenna efficient:
the area under the current distribution curve along the element. Thanks to the
controversy about current in the loading coils
please see http://www.k3bu.us/loadingcoils.htm
This is also important in the controversy with Linear Loading vs. coil. Coil
wins, current just drops along the coil, it is inline with element. LL
superimposes currents (subtracts) especially when folded along the element, not
welcome in multielement arrays.
Sooo, if one thinks that radial is just "ground" that is not significant for
antenna performance, go ahead.
No mo' centavos
73 Yuri, K3BU.us
"who needs sunspots on 160"
----- Original Message -----
From: Milt -- N5IA
Date: Friday, February 10, 2012 12:11 pm
Subject: Re: Topband: Radials help
To: Eddy Swynar , herbs@vitelcom.net
Cc: topband@contesting.com
> 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
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
>
> -----
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>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
_______________________________________________
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