[Elecraft] Unhook *ALL* connections before Lightning storm

[George Danner]

As the  CE of a TV station in South Florida we had to contend with lightning 
during about 4 to 6 months a year (spring & fall thunderstorm seasons) in 
the highest lightning strike area of North America.
We did not ever shut down but did go to generator power during lightning 
within 25 miles; as seen on the radar display with lightning strikes 
superimposed.

We had a 1,049' main tower, 2-500' microwave receive towers and a 185' tower 
at the studio not to mention 2 bureaus with antennas on the 3rd floors.
The towers had massive ring ground systems. The rings varied from 20' 
diameter to 30' diameter. each ring had 10' & 20' alternating 100% copper 
rods cad welded to a 4-0 bare copper wire. The ring was attached to the 
tower leg's 20' ground rod with 2 or 3 radials per leg. The tower ground rod 
was set in the foundation to be next to the leg and connected to the leg 
with the least angle. (remember a right angle from the leg is a 1/4 turn 
inductor!). The guyed towers also had a ring ground system around the 
anchor.

All RF, video, audio & data signals going to the tower at the site were 
protected with commercial protectors except the studio tower which was 
replaced with fiber to carry those signals.

We probably took between 6 and 10 direct hits on a good year and many many 
more on a bad year.

The new studio & one of the bureaus had a ground system constructed to 
reduce lightning damage. The building had a perimeter ground system with a 
single point power & phone and the exit panel for RF, video, audio, data and 
dc control. The ground systems was 4-0 copper with ground rods about 10' 
apart.

We did find that our damage was reduced but not eliminated. We never went 
off the air; but we did have periods where we were using redundant (back-up) 
equipment for a while until the main equipment could be repaired.

Our largest reduction in damage occurred once we deployed dissipation 
arrays! These reduce the space charge in the immediate area in hopes the 
lightning choses another location (competitor's tower). My experience with 
towers, satellite antennas & ENG microwave antennas on 50' masts on trucks 
is that the dissipation array is #1 then a ground system followed with surge 
protectors. I would not chose one but all three.

We had a saying at work about lightning protection after repairing extensive 
damage after a bad hit - Lightning protection is akin to elephant 
repellant - just because you don't see an elephant does not indicate the 
repellent actually works. I spent over 30 years in South Florida and would 
never come close to guaranteeing that we had finally done everything to 
eliminate the risk!

Not sure at what point you should stop spending money on lightning 
protection for a hobby should go. For me at my new QTH it will probably be a 
few surge protectors, grounding each mast & tiny tower and a simple ground 
improvement to the house.
73
George
AI4VZ


-----Original Message----- 
From: Rich - K1HTV

Subject: Re: [Elecraft] Unhook *ALL* connections before Lightning storm