ELECRAFT'S REPAIR SERVICE "FIVE STARS"
Locked
12
12
 
|
Vic:
Certainly I agree; likewise substations and skyscrapers take hits fairly often. Let me qualify my comments by two clarifications: 1) You can design to survive an "average" direct hit. While the cost to do so can be met by commercial broadcasters, power companies, and commercial real estate operators, it is utterly out of reach of practically all hams. 2) Even in a commercial setup, you cannot design to be completely lightning proof. You can design to withstand a certain stroke current, perhaps a current that is higher than that found in 99.9999% of strokes in your region. If so you still have a one in a million chance of being wiped out, pretty good (if perhaps prohibitively expensive) odds, but not dead-certain protection. 73, Steve AA4AK At 03:15 PM 9/1/2005 -0700, Vic K2VCO wrote: >Stephen W. Kercel wrote: > >>BTW, you cannot really design to survive a direct hit. If your antenna is >>actually struck by lightning, the antenna itself will most likely be >>destroyed, along with the coax and the rig. Also the building will suffer >>structural damage. > >I don't think that's quite true. BC stations survive direct hits every >day. I would agree, however, that it would cost more than most hams are >willing to spend. > >You would need an antenna some distance from the building, with an >appropriate lightning ground system (multiple radials, each with several >ground rods on it) at the base of the tower. Then you would need >lightning suppressors at the top and bottom of the tower for all coax and >control lines. At the entrance to the building, you would need a single >entrance panel, through which all power, antenna, telephone, etc. lines >feeding the building would pass and on which were mounted the appropriate >suppressors for all the above. At this point there would be another >ground system, bonded of course to the antenna ground system. > >If you had a separate building for a shack, this probably wouldn't be too >hard; but for a building that also serves as a home it might be difficult! > > >-- >73, >Vic, K2VCO >Fresno CA >http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
In reply to this post by Vic K2VCO
>
> I don't think that's quite true. BC stations survive direct hits every > day. > well ... sort of. I used to make a reasonable living repairing BC stations in upstate NY. Got real good at repairing HV power supplies. It is fun to stand at the base of an AM tower and watch the arc fly across the lightening arrestor. Sure helps one remember to lock the dog house gate when you leave. :) ... That was back when a 1st phone ticket was valuable. Mark AD5SS _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
In reply to this post by David-470
Stephen W. Kercel wrote:
"If your antenna is actually struck by lightning, the antenna itself will most likely be destroyed, along with the coax and the rig. Also the building will suffer structural damage." ========== In the 8 years that I lived near the Gulf Coast in Texas as W5RTQ (lots of lightning there), my tower and antenna took many lightning hits with no damage to anything whatsoever. The antenna coax was always connected to the rig. In the 29 years I've lived here in the Mojave Desert (lightning is rare here), my tower(s)/antenna(s) have been struck twice by lightning with no damage to anything whatsoever. I should mention that the towers involved had extensive buried ground radial systems made up of bare wire (I shunt feed my towers on 160/80 meters). I assume that my well-grounded towers attract lightning, but obviously that lightning is safely conducted to ground. 73, de Earl, K6SE _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
May your good luck continue.
73 Steve AA4AK At 05:29 PM 9/1/2005 -0700, Earl W Cunningham wrote: >Stephen W. Kercel wrote: > >"If your antenna is actually struck by lightning, the antenna itself will >most likely be destroyed, along with the coax and the rig. Also the >building will suffer structural damage." >========== >In the 8 years that I lived near the Gulf Coast in Texas as W5RTQ (lots >of lightning there), my tower and antenna took many lightning hits with >no damage to anything whatsoever. The antenna coax was always connected >to the rig. > >In the 29 years I've lived here in the Mojave Desert (lightning is rare >here), my tower(s)/antenna(s) have been struck twice by lightning with no >damage to anything whatsoever. > >I should mention that the towers involved had extensive buried ground >radial systems made up of bare wire (I shunt feed my towers on 160/80 >meters). I assume that my well-grounded towers attract lightning, but >obviously that lightning is safely conducted to ground. > >73, de Earl, K6SE _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
In reply to this post by David-470
"If your antenna is actually struck by lightning, the antenna itself will
most likely be destroyed, along with the coax and the rig. Also the building will suffer structural damage." ========== 1980's Lightning Strike Shelby, Ohio Random wire to old oak tree in back yard--------Vaporized 2m 1/4 antenna coat hanger wire in SO239-----antenna survived but RG58 coax vaporized to chunks of insulation with longest about 1 inch in length--no metal left Trapped ground mounted vertical------arced over leaving carbon track in base part Splintered charred wood where conductors came in thru wood at window of house. No Radio damage because all antennas were disconnected just inside window---was lucky that indoors escaped damage. Submersible water pump and cordless phone base unit zapped also Paul WD8OJL KX1 SN1082 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |