It seems to me that whether or not one grounded the far end of a radial would
make no difference. I don't see why one would want to ground the end of their
radial, but if it was done with a ground rod that's not really much of a
"ground" for rf. Think about it: a single ground rod at the base of a vertical
isn't going to provide much of a "ground" -- that's why we need radials. A
ground rod at the far end of a radial will provide a similar crummy rf ground
thus limiting any effect it would have on that radial at rf.
Also, for any reasonable number of radials resonance doesn't really matter
since its providing a ground screen (for on- or under-ground radials). The
radial network is a non-resonant counterpoise.
-Bill
Sent from my iPhone
On Jan 25, 2014, at 3:58 PM, "Charlie Cunningham"
<charlie-cunningham@nc.rr.com> wrote:
> I generally agree with you, Bob - especially with regard to not grounding
> the far ends of 1/4 wave radials!! After all what we are trying to
> establish is a low-impedance "image plane" for the vertical radiator to be
> fed against! A 1/4 wave wire, grounded at the far end would have a high
> impedance to ground at the base, or feed-point, of the antenna! Makes no
> sense! Would not result in a very favorable "driving-point impedance!
>
> 73,
> Charlie, K4OTV
>
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bob
> Eldridge
> Sent: Saturday, January 25, 2014 3:46 PM
> To: topband@contesting.com
> Subject: Topband: Grounding the ends of radials
>
>> I posted this on TowerTalk and I got a couple of responses as to why
>> the ends of ground radials should not be grounded.
> Isn't it dependent on whether you want the radials resonant or not? And
> if you do want them resonant, on the length of the radial?
> It doesn't make sense to ground the far end of a quarter wave radial if
> you want a low impedance at the base of the antenna. It does make sense if
> you have short radials and want to intercept the "return current".
> Bob VE7BS
>
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