I'm thinking of stringing a long wire attenna in my attic (the length of my one storey is about 40 feet). Does this pose a problem as far as attracting lightning if left ungrounded, and unattached when not in use?

Here's the scoop with lightning: with the wire in the house, the lightning is not going to strike the wire unless it strikes the house first. The wire does not have some magic magnetic pull that is going to cause lightning to strike your house any more than it already does (hopefully not at all). Strung outside, next to the house, it is no more likely to be struck than the house, the trees around the house, and the power wires around the house. The only problem with it being out here is that it can pick up charges in the air from lightning strikes nearby, which can damage some electrical equipment. This is not so much a fire hazard as it is an electrical equipment danger. Grounding the antenna during a storm or putting a lightning arrestor on the antenna helps send these charges out of the antenna. If you ground the antenna, you will not receive stations, so an arrestor is a better idea. They can be found on eBay. Lightning arrestors only protect from charges in the air. If lightning strikes your antenna, you will probably find a melted or blown up arrestor. Furthermore, the lightning will probably strike your house, which is nearby, too, if it doesn't strike the house first.

When trees and chimneys are wet, they are just as good of conductors as the antenna. If the antenna is the tallest object around, it is more likely to be struck than nearby objects. If it is lower than everything else, then it is no more likely to be struck than anything else. I just want to make that perfectly clear, because people have this notion that just because it is metal, it will send a call out to all lightning to come its way. It can be struck by lightning, but is no more likely to be struck than other nearby objects. Certainly the lightning is not going to seek out a thin little wire when it can have a big wet tree, though some may jump from the tree to the wire if the wire is near the tree.

Here's something to put it all into perspective: if the lightning can travel thousands of feet from a cloud, it's going to strike whatever it wants to strike. Though you are safe in a car because there's a metal shield around you to divert the charge (though the charge can also explode the gas tank), the lightning will jump the rubber tires as though they were not there (the lightning will probably jump directly from the car floor to earth). Same holds true if you feel that you are safer simply because you are wearing rubber soled shoes. The lightning will think no differently of you than if you were in your bare feet.

Thomas

Thomas,

I have a question about lightning arrestors: I found an old ceramic Philco lightning arrestor in the back of an old radio I bought recently. It has two terminals, one marked for the antenna, one marked for ground. On the reverse side, there is a channel between the terminals filled with some kind of hard brown bakelite or epoxy or something. Anyway, there is no continuity between the two terminals, which is probably good, but should there be a shunt of some kind that connects the antenna terminal to the ground terminal when you want to ground the antenna? Or would whatever the brown material in the channel on the reverse side of the arrestor be the medium for the connection between the antenna and ground? I've never seen one of these before.

Thanks, Jeff

:Here's the scoop with lightning: with the wire in the house, the lightning is not going to strike the wire unless it strikes the house first. The wire does not have some magic magnetic pull that is going to cause lightning to strike your house any more than it already does (hopefully not at all). Strung outside, next to the house, it is no more likely to be struck than the house, the trees around the house, and the power wires around the house. The only problem with it being out here is that it can pick up charges in the air from lightning strikes nearby, which can damage some electrical equipment. This is not so much a fire hazard as it is an electrical equipment danger. Grounding the antenna during a storm or putting a lightning arrestor on the antenna helps send these charges out of the antenna. If you ground the antenna, you will not receive stations, so an arrestor is a better idea. They can be found on eBay. Lightning arrestors only protect from charges in the air. If lightning strikes your antenna, you will probably find a melted or blown up arrestor. Furthermore, the lightning will probably strike your house, which is nearby, too, if it doesn't strike the house first.
:
:When trees and chimneys are wet, they are just as good of conductors as the antenna. If the antenna is the tallest object around, it is more likely to be struck than nearby objects. If it is lower than everything else, then it is no more likely to be struck than anything else. I just want to make that perfectly clear, because people have this notion that just because it is metal, it will send a call out to all lightning to come its way. It can be struck by lightning, but is no more likely to be struck than other nearby objects. Certainly the lightning is not going to seek out a thin little wire when it can have a big wet tree, though some may jump from the tree to the wire if the wire is near the tree.
:
:Here's something to put it all into perspective: if the lightning can travel thousands of feet from a cloud, it's going to strike whatever it wants to strike. Though you are safe in a car because there's a metal shield around you to divert the charge (though the charge can also explode the gas tank), the lightning will jump the rubber tires as though they were not there (the lightning will probably jump directly from the car floor to earth). Same holds true if you feel that you are safer simply because you are wearing rubber soled shoes. The lightning will think no differently of you than if you were in your bare feet.
:
:Thomas

The brown material is simply a cement that holds the electrical parts in place within the recesses that have been molded into the porcelain for the electrical parts. A lightning arrestor is simply a device that sends high voltage to ground without connecting the antenna to ground. It does this either by simply having an arc gap (like a spark plug), or with a tube filled with a gas (such as neon or argon). Within the tube are two electrodes just like an oridinary arc gap. The gas within the tube makes it easier for high voltages to jump the gap, as most gasses used for illumination will operate at voltages as low as 80 or there-abouts, where-as a spark plug usually requires about 10-20,000 volts to spark. If there was a device that always connected the antenna terminal to ground (like a resistor), the efficiency of your radio would be sacrificed. This is why there is no continuity across the terminals on a lightning arrestor. If you wish, during storms you may shunt across the arrestor to ground. You can also run wires under the window from the terminals on the arrestor, and connect these to a switch. This will make a neat and convenient means of grounding your set. With a lightning arrestor in place, though, you should not worry about this too much unless the antenna is connected to a solid state radio. The arrestor provides enough protection.

Also, when erecting antennas, be sure to use insulators that do not become saturated with water, as this will ruin your set's performance during or right after a storm. I know that people say that it's not a good idea to listen to a radio during a storm, but sometimes this is when it is critical. Honestly, unless your antenna is mounted on top of your house or higher, lightning is not going to directly strike the antenna unless the lightning is headed for your house anyway.

Thomas