A good ham friend of mine in Southern California has been a broadcast
engineer for most of his life.
He has worked at several stations over the years, and by the FCC, he has to
measure the field strength annually at set locations at various compass
points and distances.
At his last station they had to null out their signal in one direction so
as to not interfere with another BC stations hundreds of mile away.
Anyway, I do remember seeing their radial system, there were a lot,
especially on their main TX tower. They used a smaller tower with a few
elevated radials in the direction to attenuate their signal as required by
the FCC.
My story may not contribute to this dialogue but I found this all very
interesting.
Personally, for my 72ft top loaded 160m vertical. I have abt 80 radials at
67 ft and 135 ft long. I feel I have a decent signal on 160m but there are
others that do beat me out in the pile ups. I am in the Arizona high desert
and have poor soil conductivity.
Currently, on my 80m 4SQ TX system I have 48 radial 67ft per vertical. I
use a Comtek controller, and noted that Comtek suggests 60 - 1/4 wave
radials.
Ray
N6VR/W7YA
On Fri, Dec 2, 2022, 10:47 AM Mpridesti via TowerTalk <
towertalk@contesting.com> wrote:
> In addition to what Ed, N1UR suggests, I also measure the resistance
> between the center conductor and the shield of the coax in the high meg ohm
> scale of the meter. Of course you want an open circuit and you might see
> this at a low resistance scale but problems that are attributed to water
> egress are found in the high resistance scale.
>
> Over the years, I have found some feed cables to my verticals having high
> resistance in the meg ohms. In most cases, cutting off the last two inches
> and reterminate the ends solved the problem.
>
> Regards,
>
> Mark, K1RX
>
>
> > On Dec 2, 2022, at 11:02 AM, Jorge Diez - CX6VM <cx6vm.jorge@gmail.com>
> wrote:
> >
> > OK thanks Paul
> >
> > how can you measure that a radial system is still good over the years?
> >
> > Maybe the cable is degraded, or is cutted in some points if animals are
> > around.
> >
> > Is any easy way to determine that the radial system on a vertical antenna
> > is still good?
> >
> > thanks!
> > Jorge
> > CX6VM/CW5W
> >
> >> El vie, 2 dic 2022 a las 12:06, Paul Christensen (<w9ac@arrl.net>)
> escribió:
> >>
> >> Jorge,
> >>
> >> N6LF's material is based largely on measured results in support of
> >> theory.
> >>
> >> Paul, W9AC
> >>
> >> -----Original Message-----
> >> From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Jorge
> >> Diez - CX6VM
> >> Sent: Friday, December 2, 2022 9:57 AM
> >> To: Paul Christensen <w9ac@arrl.net>
> >> Cc: Ignacy Misztal <no9e@arrl.net>; tower and HF Antenna Construction
> >> Topics. <towertalk@contesting.com>
> >> Subject: Re: [TowerTalk] 16om vertical and the number of radials
> >>
> >> I think Paul wants to know the "real" situation, not theory. He want to
> >> know if the theory is 100% in accordance with real big stations with
> many
> >> radials on the antennas
> >>
> >> 73,
> >> Jorge
> >> CX6VM/CW5W
> >>
> >> El vie, 2 dic 2022 a las 11:50, Paul Christensen (<w9ac@arrl.net>)
> >> escribió:
> >>
> >>> Ignacy,
> >>>
> >>> There's a lot of published information that addresses your question.
> >>> Some material is rooted in commercial applications and even more in
> >>> the amateur literature where modeling is compared with measured
> results.
> >>>
> >>> As a starting point, I would carefully read Rudy Stevens' material:
> >>>
> >>> https://www.antennasbyn6lf.com/design_of_radial_ground_systems/
> >>>
> >>> Paul, W9AC
> >>>
> >>> -----Original Message-----
> >>> From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Ignacy
> >>> Misztal
> >>> Sent: Friday, December 2, 2022 9:25 AM
> >>> To: tower and HF Antenna Construction Topics.
> >>> <towertalk@contesting.com>
> >>> Subject: [TowerTalk] 16om vertical and the number of radials
> >>>
> >>> Do more radials on a 160m vertical bring more improvements than shown
> >>> by simulation?
> >>>
> >>> Most simulations show that going above 32 radials on 160m brings
> >>> minimal improvement, say 1 db to 2 max. Even for low angle signals.
> >>>
> >>> On the other hand, some really loud stations n 160m, say 5-10 db above
> >>> the crowd, use a massive amount of radials. This is for inland
> >>> stations, far away from salt water.
> >>>
> >>> Is there any discrepancy between modeling and real life performance
> >>> with the number of radials? Does adding radials beyond 32 help much?
> >>> Any real stories?
> >>>
> >>> Ignacy NO9E
> >>> _______________________________________________
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> TowerTalk mailing list
> >>> TowerTalk@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/towertalk
> >>>
> >>> _______________________________________________
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> TowerTalk mailing list
> >>> TowerTalk@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/towertalk
> >>>
> >>
> >>
> >> --
> >> 73,
> >> Jorge
> >> CX6VM/CW5W
> >> _______________________________________________
> >>
> >>
> >>
> >> _______________________________________________
> >> TowerTalk mailing list
> >> TowerTalk@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/towertalk
> >>
> >>
> >
> > --
> > 73,
> > Jorge
> > CX6VM/CW5W
> > _______________________________________________
> >
> >
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
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>
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