[Antennas] Dumb question?

Sun May 17 19:44:07 EDT 2009

Ron-
Prepare for strong differences of opinion. Many will say that charge 
dissipation is a myth, and many will say it works. I tend to be on the 'it 
works' side, based on experience working for 38 years in a Rocket fuel plant 
where all buildings were made to Army Ordnance standards. These standards 
include "Uffer" grounds and pointed rods above.
In that time, we only had one lightning induced fire, and that was 
attributed to a painting crew having disconnected the overhead system, and 
not re-connecting it.
Bill-W4BSG
----- Original Message ----- 
From: <bonddaleena at aol.com>
To: <antennas at mailman.qth.net>
Sent: Sunday, May 17, 2009 3:00 PM
Subject: [Antennas] Dumb question?
> Hi, here is a question I would like to put before the list....
>> I have just finished getting my 2 - 95 foot towers up. They are well
> engineered and guyed VERY well with 1/4" EHS guy wire.
> The towers are well grounded with low imped copper strap from each leg
> to a system of 8' ground rods all interconnected.
> I have had tall towers like this at my last 4 QTHs and never had a
> problem with lightning DIRECTLY hitting a tower. I have had some 'near
> misses' which have taken out several mast mounted VHF and UHF GaaSFET
> preamps , until I learned how to protect them.
>> However, I was watching a special last night on Ben Franklin and they
> went into great detail about how he invented the 'lightning rod'
> concept.
> I have read extensively about this subject, but still have this
> question on my shrinking mind:
>> Since I leave near the thunderstorm capitol of the USA (Florida), would
> I gain any safety by installing a very pointed conductor at the very
> top of my tower's mast?
>> One tower will have a pair of 432 MHz long yagis at 115'. They will be
> fed with 7/8" CATV hardline and have the preamp near the rotor.
> I have ground straps to bypass the rotor. The antennas are all at DC
> ground, so there would be a direct path to ground for everything on the
> tower.
>> My feeling is that by placing a sharply pointed 'tip' to the top of the
> mast will help dissipate a charge before it builds to strike potential.
> As you are aware, this is how Ben's stuff works. Lightning rods cannot
> withstand a direct 'hit'. They are for dissipation purposes.
>> OR, am I inviting a strike with the pointy rod????
>> I've not seen this topic discussed before.
>> Thank you in advance.
>> ron
> N4UE
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