There has been a lot of talk about lightning protection. Seems each person
is satisfied with their setup for protection, or the lack of same. And
there are many testimonials to back up the claims. Well, here is another.
My tower (Rohn 45 equivalent) went up in 1999 with F12 C-4XL at 152 feet and
a 144/440 base vertical 5 feet above. The vertical was planned for a
digipeater but was never used. It had a 50 foot coax cable attached that
was rolled up and taped to a leg near the rotator. The base of the tower
has a Rohn 45 short section buried in 5 feet of concrete. Three 8-foot
ground rods surround the base and are connected to each leg with 1 inch
copper braid. All coax and control cables are attached to Polyphaser
arrestors at the bulkhead leading to the shack. The bulkhead is tied to two
ground rods which are also connected to the tower and power service ground
rods.
There have been four observed direct strikes to the tower over the last 5
years, and who knows how many more that were not observed. Weather here on
the Gulf Coast yields many opportunities for thunderstorms. Until the last
strike, the only damage has been to telephones, TVs and computers. This was
due to my lack of knowledge about the proper use of surge protectors for
phone lines and Cat 5 Ethernet cables. The last strike finally did some
major damage to ham equipment. The PA in the IC775 transceiver was blown.
The Yaesu GS800SDX runs at slowest speed. The 144/440 antenna is in pieces.
Additionally, two of the five PCs on the LAN were damaged and one monitor
was blown, this in spite of good protection.
The bottom line is that a bolt of lightning can and will defeat the best
plans. So, good luck!
Keith
WD5DXL
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Tower (K8RI)
Sent: Tuesday, July 06, 2004 1:50 PM
To: Alan AB2OS; towertalk reflector
Subject: Re: [TowerTalk] RCS-4 Coax Switch
My tower has been taking about three direct hits a year on average, although
it's already had three this year. No equipment damage this year. A while
back I did lose one computer, or a good portion of it but it had no surge
protection at that time. I also lost the PolyPhaser in the line to the 440
array which is the top most thing on the tower.
I now use APC UPSs on all four computers. The last direct hit was about a
month ago. The 144/440 rig was running as were all the computers. My
network went down and came right back up. No damage to any thing in the
house.
After one storm my neighbor asked me if I had any damage. I told him no and
asked why. He said he had just started to go out their patio door (which
faces the tower) when the tower took a direct hit. Other than all four UPSs
showing a transfer of about 5 seconds (all at the same time) for line noise
nothing was amiss.
I do have to check the PolyPhasers for loss after something like that, but
so far they all seem to be doing fine.
Roger Halstead (K8RI, EN73 & ARRL Life Member) N833R, World's Oldest
Debonair (S# CD-2) www.rogerhalstead.com
> So do you have any comment on this exchange copied from the
> alt.home.repair newsgroup (originally concerning whole-house
> power-line surge arrestors):
>
> ">Reality check here....I don't care what surge protection you use, if
> >>lightning hits your stuff its fried.
>
> Incorrect. The building I work at (TV station) has equipment
> connected to an antenna on the top of a tower that has an actual
> structure height of
> 1,976 feet
<snip for bandwidth>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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