[TowerTalk] 16om vertical and the number of radials

Fri Dec 2 13:29:15 EST 2022

I suspect the main reason some folks disparage theory is the failure to take into account differences between the theoretical installation and their own.

Maybe Sevick put his short vertical in an open field and you set yours next to a metal shed. Perhaps Cebik used a non-conductive support and you hung yours from a metal tower. Perhaps Brown constructed and tested a choke for his vertical and you dismissed a choke as unnecessary.

73, kelly, ve4xt 

Sent from my iPhone

> On Dec 2, 2022, at 12:21 PM, Raymond Benny <rayn6vr at gmail.com> wrote:
> 
> 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 at 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 at 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 at 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 at contesting.com> On Behalf Of Jorge
>>>> Diez - CX6VM
>>>> Sent: Friday, December 2, 2022 9:57 AM
>>>> To: Paul Christensen <w9ac at arrl.net>
>>>> Cc: Ignacy Misztal <no9e at arrl.net>; tower and HF Antenna Construction
>>>> Topics. <towertalk at 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 at 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 at contesting.com> On Behalf Of Ignacy
>>>>> Misztal
>>>>> Sent: Friday, December 2, 2022 9:25 AM
>>>>> To: tower and HF Antenna Construction Topics.
>>>>> <towertalk at 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 at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>> 
>>>>> _______________________________________________
>>>>> 
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> TowerTalk mailing list
>>>>> TowerTalk at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>>> 
>>>> 
>>>> 
>>>> --
>>>> 73,
>>>> Jorge
>>>> CX6VM/CW5W
>>>> _______________________________________________
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> TowerTalk mailing list
>>>> TowerTalk at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/towertalk
>>>> 
>>>> 
>>> 
>>> --
>>> 73,
>>> Jorge
>>> CX6VM/CW5W
>>> _______________________________________________
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> TowerTalk mailing list
>>> TowerTalk at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/towertalk
>> 
>> _______________________________________________
>> 
>> 
>> 
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk