Hi Dave,
I would suggest you purchase and read the new ARRL book: Grounding and
Bonding for the Radio Amateur.
It has everything you need.
73 -- Larry -- W1DYJ
-----Original Message-----
From: David J "Dave" Windisch
Sent: Friday, July 27, 2018 11:43
To: towertalk@contesting.com
Subject: [TowerTalk] how best to protect RC ham gear from lightning
Subject: how best to protect RC ham gear from lightning
Hi, Steve, and all concerned:
I'm simply nervous and jerky about how best to protect RC ham gear from
lightning, since I won't be around to disconnect cables "the old way".
My remote site is a former AT&T microwave relay site, on 920ft ASL property,
near Cincinnati OH.
There's a pic on my QRZ page.
The tower is 120ft tall to the approach beacon plate.
The bunker is about 57ftX57ftX16ft.
A retired AT&T engineer familiar with these sites, told me there is a ground
mat under the entire site, to which _everything_ is connected, probably even
the fence around the site.
20-mile el profiles to major world DX regions taken from GOOGLE EARTH, as
well as HFTA, show the site as "a nice bump" of good ole Ohio farm dirt,
iow, a good potential lightning target.
Yet, minute inspection of the entire tower top yields nothing I can
interpret as evidence of lightning strikes during the 50-odd years the site
has existed: there are no telltale marks in the paint or galvanizing.
Electricity, antenna feeds, and internet enter the bunker, from under
ground, at a single point.
A home 1.9mi away on 750ft ground(!) took a _major_ hit last summer. Lotsa
damage, no injuries.
My thoughts, so far, are to start from the highest point, with:
1. A mast with rotator, bonded to the tower, with the topmost antenna
down, say, 5ft from the mast top so the mast forms a sorta lightning rod
2. Cable shields tower-bonded top and bottom
3. All cables in a trench to the single point bunker entry
4. Control cables protected by, eg, ICE or similar voltage clamps
I'm stuck here:
How can I best protect the sensitive data and rx/tx ports on the gear, which
will be set up on a grounded metal operating table, inside the bunker?
Brgds,
Dave, N3HE
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