[TowerTalk] Antenna to Shack Ground Connection

[Roger (K8RI) on TT]

On 1/28/2015 1:57 PM, Patrick Greenlee wrote:

Not a debunking, but maybe a modification<:-))

I have a 100' 45G that had a 30'  mast extension in the center of a 200 
X 200 lot. One multiple strike abt 6, or 7 years ago hit all around us 
except to the S, yet it ignored my system that was almost in the center 
of the strike zone.
  http://www.rogerhalstead.com/ham_files/Tower29.htm  I was in a bit 
better shape back then.  Yet as I've mentioned a number of times, it 
took 17 visually verified hits in 6 years and nothing in the 8 years 
since.  Oh!  That strike did a lot of damage in the neighborhood.

The only thing predictable about lightening, is its unpredictability.

73

Roger (K8RI)


> The old rule of thumb for lightning protection from over head 
> dissipation devices (high metal roofs, lightning rods, grounded 
> towers, etc. is a 30 degree cone angle.  This is NOT a guarantee but a 
> tendency.  I think more is better and would not find fault with a 
> ground wire a ways above coax or control leads but would encourage 
> ground rods along the way so as to not encourage a great deal of 
> coupling between lightning generated ground wire and "other" 
> conductors below it.
>
> Patrick  NJ5G  (now stand by for a total debunking of my comments...)
>
>
> On 1/28/2015 12:30 PM, David Gilbert wrote:
>>
>> I don't have the expertise to be sure about it, but it always seemed 
>> to me that it would be best to run the ground wire (grounded at both 
>> ends and maybe a few places in between) in the same trench as the 
>> coax ... but some distance above them ... in order to provide a sort 
>> of shielding effect for the coax against induced currents from nearby 
>> lighting bursts.  I was once told that the electric utilities run a 
>> ground line at the top of utility poles above the actual power lines 
>> for a similar purpose.
>>
>> Possibly induced currents in the ground wire would still couple to 
>> the coax anyway, but I certainly don't see how running the ground 
>> wire with the coax would be any worse than running them separately.
>>
>> 73,
>> Dave   AB7E
>>
>>
>>
>> On 1/28/2015 8:43 AM, Cox, Norman R. wrote:
>>> Dear Group:
>>>
>>>      I am now ready to connect the tower grounding rod network to  
>>> the shack grounding system.  The crank-up tower is about 30 feet 
>>> from the shack.  Is it preferable to run the ground connection 
>>> between the two along with signal cables?  Or is it better to run 
>>> the grounding connection not so close to the signal cables?  I've 
>>> seen people do it both ways, and can see a possible benefit either 
>>> way, but a lightning strike could throw either idea out the window.
>>>
>>> Thanks,
>>>
>>> Norm
>>> KE0ZT
>>>
>>>
>>> _______________________________________________
>>>
>>>
>>>
>>> _______________________________________________
>>> 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


-- 

73

Roger (K8RI)


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com