[RFI] Question re: Whole House Surge Protection
w8ji at contesting.com
Wed Jul 21 20:32:35 EDT 2004
> My neighborhood was zapped on July 4th. An indirect hit
> powerline surge at our house that nailed my Omni-6+ and
> (wireless phone, answering machine, home alarm control
> Oddly, while our hit came trhough the AC line, my
neighbor was hit
> through his cable connection (our TVs were not hit).
The first thing I'd do is review the proper way to ground
your utilities and radio feedlines. I'd be willing to bet
neither you nor your neighbor have good single point grounds
for all wiring entering the buildings, and do not use single
point hubs at TV sets and the like.
Every feedline entering the dwelling should be through a
grounding block that has a very low impedance to the telco,
CATV, and power line grounds.
When that isn't done, lightning loops through the building
and wipes out all sorts or equipment in weird ways, and a
lightning protector almost certainly won't do a thing.
I have a 318 ft tower that gets hit several times a year, I
have smaller 200 ft and 160 ft towers, and miles and miles
of antennas and cables that remain connected 24/7 every day
of the year. In spring I took a super bolt that actually
melted feed cables, the telephone lines, and burned about 2"
off the top of a two meter 4 bay dipole at the top of the
318 ft tower.
I don't have a single polyphaser or anything else, although
every "group" of electronic devices has a common point
"ground" where all cables enter and leave, and before any
cables come into the house they go through bulkhead
feedthroughs that are common to the utility company
I never lost a modem, never lost a TV set, and never lost
anything in my shack except a single 2N3904 transistor that
switches relays in my Beverages. Everything was plugged in,
everything was connected to the antennas.
While I not saying surge protection should be ignored, how
you connect things provides nearly all of the energy
diversion. If you don't follow proper lead routing and
grounding, there isn't a suppressor in the world that will
protect your gear.
More information about the RFI