On the day of the Net we had a bit of unexpected rain. For most of us, rain, and especially lightning, affects our radio activity. To reduce my exposure to lightning, I usually will move my radio operation to a battery powered radio hooked to an attic antenna. The base radio gets unplugged from AC. I physically unplug my power supply from the wall. In addition, I unscrew the PL-259 connector from the back of the radio and let it dangle, not allowing the antenna connector to touch anything. I do not ground the plug.
My question, to those who check in tonight is: What do you do with your radio equipment during a storm?
Ron, kb5vdb, said that he didn't know if there is anything you can do to protect yourself from a lightning strike. Air is the best insulator that we know of, and lightning passes through air easily. He mentioned that he unplugs from the AC source and may hook to a magnet mount antenna. He mentioned that he had a friend that was hit by lightning while driving a tractor. The lightning hit him in the head and came out of his foot; he lived.
The story below was found at: http//www.dailycognition.com/index.php/2007/04/27/story-of-a-man-who-was-struck-by-lightning-7-times.html.
"US Park Ranger Roy C. Sullivan from Virginia holds the record for the person most struck by lightning - and living to tell the tale. Between 1942 and 1983, Roy has the dubious distinction of being struck by lightning seven times. He was known as the Human Lightning Rod.
The first lightning strike in 1942 happened as he was working in a lookout tower and the lightning bolt shot through his leg and knocked his big toenail off.
In 1969 while he was driving along a mountain road a second strike burned off his eyebrows and knocked him unconscious. Another strike just a year later, while he was walking across his yard to get his mail, left his shoulder seared.
He was standing in the office at the ranger station in 1972 when lightning set his hair on fire and Roy had to throw a bucket of water over his head to cool off. A year later, after his hair had grown back, a lightning bolt ripped through his hat and hit him on the the head, setting his hair on fire again. It threw him our of his truck, knocked his left shoe off and seared his legs. A sixth strike hit him in 1976 while he was checking on a campsite, injuring his ankle.
The last lightning bolt to hit Roy in 1977 happened while he was fishing. It sent him to the hospital with chest and stomach burns.
Roy Sullivan was never killed by lightning - he committed suicide while in his 70's in 1983 reportedly distraught over the loss of a woman."
Mike, ke5yoo, added that on a direct hit, there's not a lot that you can do. As long as you have a good solid single point ground at your antenna, then you shouldn't have a problem. As the voltage increases from a surge, the potential may rise in all of your equipment, but your equipment needs to be unplugged. If you get hit by lightning in another part of the house, and the lightning finds another path through your equipment, you'll have damage.
It stands to reason that your exposure to lightning, or subsequent power surges resulting from lightning, is related to the exposed inputs into your equipment. For most of us there are two avenues that allow this. The AC input to your equipment is one and the antenna input to your equipment is the other. If you have computer or other devices connected to your equipment, they may also provide an avenue.
The ARRL has a two-part article that addresses Lightning Protection. The first part is found at: http://www.arrl.org/tis/info/pdf/0206056.pdf . The second part can be found at: http://www.arrl.org/tis/info/pdf/0207048.pdf .
Tim, ke5vas, mentioned that American Power Conversions has a number of Uninterruptable Power Supplies that provide a level of protection against surges, particularly power drops. He said that he is at the end of a line and suffers a lot of power drops.
APS UPSs are available from office supply stores such as: Office Depot, Office Max, and Staples. They can also be found at electronics stores, like Best Buy.
More can be found on APS at: http://www.apc.com
Paul, ae5pb, suggested the use of Polyphaser as a source for protection. "Various amateur catalogs (AES for sure) stock some Polyphaser products. Electronics supply houses generally stock a more comprehensive inventory. You can find bunches of them on the internet. These are the industry standard - USACE uses tons of them in radio and also remote sensing applications. I'll bet I've written purchase orders for over a hundred of them. Their lightning protection handbook is the best out there.
Hoffman boxes are NEMA (National Electrical Manufacturers Association) spec enclosures. Though this is a specific brand, it's kind of like kleenex or band aid, and has come to mean any such box.
AES sells one that will hold Polyphaser copper single point ground panel, with in/outs for two coax lines. I'm going to use one with three coax ports, with the Polyphasers on the ground panel inside."
Polyphaser's website is located at: http://www.polyphaser.com .
Dave, ke5lnn, said that he has extensively used Polyphasers on his rig on every coax. He had the electric company put in a surge suppressor on the other side of the meter. During a storn he unplugs everything that has a wire in it. The idea is that the coax comes into a connector outside with a copper plate. He said that he's also heard that you can use a glass insulator, like a bottle to put your connector into inside. But that could create a glass bomb!
Note: I couldn't find anything on the internet that mentioned the use of glass insulators for isolating your PL-259 connector. If anyone knows anything about this, I'd be interested in hearing about it. I imagine that unless the glass is pure with virtually no air pockets, then the heat from a lightning strike could possibly cause the air in the pockets to expand, quickly, causing a "glass grenade", much like what Dave mentioned above.
Hank, ae5mn, mentioned that his exterior antenna gets disconnected during a storm and that in the future he intends to disconnect the power as well.
Ron, kb5vdb, added that most antennas are DC grounds anyway, but that Hank's, being a j-pole, will not be.
