Well, I guess I've had some very rare hits since my TA33 at 25' on my parent's home years ago got hit by lightning and my Cushcraft R7000 vertical mounted at 10' above the ground got hit just 5 years ago here in Texas. My radios were disconnected from the feedline, but still connected to everything else. No damage in the shack in either case except during the recent hit, my DSL modem was taken out.
My neighbor's wife happened to be looking out her kitchen window and saw the lightning hit the vertical. The coax feedline to the antenna went down to ground level, next to my pool filter motor and then into the house. The lightning grounded through the pool filter pump motor - blowing a hole in the side of the coax http://nj-bob.smugmug.com/Radio-Stuff/Lightning-Strike-052505/556399_qL6ML#2 3130433_v6ezB-A-LB It toasted the filter pump motor, the freeze protector and also the pool heater. All of it had to be replaced. The antenna's matching network exploded and sent shards of plastic flying all over the yard and in the pool. More photos here: http://nj-bob.smugmug.com/Radio-Stuff/Lightning-Strike-052505/556399_qL6ML#2 3130442_qkYFL I wonder if I had the antenna grounded through some sort of protective device that I might have avoided the resulting damage? 73, Bob W5OV -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Tom W8JI Sent: Friday, March 19, 2010 6:36 PM To: Charles Teeter; Elecraft@mailman.qth.net Subject: Re: [Elecraft] [OT] Grounding Antenna when not in use After I get my kit built, I¹ll be operating with a windom antenna on 40 10. It¹s been suggested that when I¹m not operating, I should disconnect the rig from the antenna and run the antenna to ground. I¹ve never done that in the past when I operated with wire antennas or my vertical, but it does make sense as a safety precaution. I¹m wondering if anyone has any suggestions about the best way(s) to do that? Are there any pieces of equipment that you would recommend to simplify the process? Any help would be greatly appreciated. Thanks.>> Chuck, Nearly all the time when there is serious damage, it comes from a loop from power lines to your antenna and station ground. http://www.w8ji.com/ground_systems.htm You either MUST have a proper station ground bonded to the power mains ground and a bulkhead entrance, or you really would have to take the rig totally out of line. No power supply connections, computer connections, antenna, or anything. Although it is popular, grounding the antenna when off really means next to nothing. It can help if a hit is a mile away, or from p-static charging, but it won't do a thing if lightning hits the mains (very common) or the antenna (very rare unless you have a tall tower). For automatic antenna disconnect and static shielding you really need a double-make double-break relay, in a proper box with proper layout, to totally isolate the center conductor. It has to be a properly configured double-make double-break that grounds the transfer bar when the relay is off. Any other type of relay or switch is not secure at all. Tom ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
