[TowerTalk] 16om vertical and the number of radials

[Grant Saviers]

You could measure the current in each radial with a clamp on RF ammeter. 
  Especially useful if the original currents were measured.  This might 
separate damaged from ok radials although for my 8 radial elevated 
system new, there was a 3:1 variance in currents due to what each radial 
was near/over.  My sum of radial currents did equal the vertical element 
current which showed the feedline was well enough choked.

I used an MFJ-843 meter which works even with a poor clamp on the 
ferrite core sensing element.  It is not well calibrated so bench cal 
with a dummy load and transmitter at various power levels on the 
frequency of use is important if accurate current values are needed.

There are also lots of DIY designs, but the MFJ has an amplifier for the 
low amperage you might find with large numbers of radials at a TX power 
level you are comfortable with.

Grant KZ1W

On 12/2/2022 08:01, Jorge Diez - CX6VM 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
>>> _______________________________________________
>>>
>>>
>>>
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>>
>>
>> --
>> 73,
>> Jorge
>> CX6VM/CW5W
>> _______________________________________________
>>
>>
>>
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>