outdoor FM antenna - Lightening strike risk?

[scott911]

Hi,

I'd like to connect a unidirectional FM antenna (half wavelength unit I think it's called) to my reciever. Various web sites instruct that I put it as high up as possible.

I do live in a dell, and am replacing the "little wire thingy" with a better antenna in order to get better reception - BUT I'm not so into radio that I want to risk equipment by inviting a lightening bolt into my house and reciever.

Anything to worry about here? - If so, I think I may just mount it indoors - to a first story high wall in my porch.

btw - I live in western new york - we've not know for getting much lightening... but...

 

[bandphan]

FYI some cable companies have the FM feed on their lines. I use a trek HD antenna that does FM also.

 

[Adam]

I have an outdoor TV antenna, and it is connected to a ground rod as a measure of protection against lightning. The instructions were very clear about doing that. The antenna that you have (or are thinking about getting) might have similar instructions and hardware. I have the signal cable routed through a surge protector, but I honestly think that I'll have larger problems then my electronics getting fried if a get a direct lightning strike on my patio roof.

 

[scott911]

but I honestly think that I'll have larger problems then my electronics getting fried if a get a direct lightning strike on my patio roof.

Adam - I'm shocked - what kind of audioholic are you? It's the equipment you need to worry about, not the house!

 

[Adam]

Adam - I'm shocked - what kind of audioholic are you? It's the equipment you need to worry about, not the house!

Golly, I'm an audioholic living in shame, now!

I was actually more worried about me and the pooch. The antenna is about 15 feet from where I sit when watching TV. If I made it through, the chair probably wouldn't.

 

[speakerman39]

Golly, I'm an audioholic living in shame, now!

I was actually more worried about me and the pooch. The antenna is about 15 feet from where I sit when watching TV. If I made it through, the chair probably wouldn't.

Hey Adam, don't fret my friend. Benjamin Franklin beat you to the punch............LOL!!!! Word has it, that he was the first audioholic.

Cheers,

Phil

 

[skizzerflake]

Hi,

I'd like to connect a unidirectional FM antenna (half wavelength unit I think it's called) to my reciever. Various web sites instruct that I put it as high up as possible.

I do live in a dell, and am replacing the "little wire thingy" with a better antenna in order to get better reception - BUT I'm not so into radio that I want to risk equipment by inviting a lightening bolt into my house and reciever.

Anything to worry about here? - If so, I think I may just mount it indoors - to a first story high wall in my porch.

btw - I live in western new york - we've not know for getting much lightening... but...

An antenna isn't any more vulnerable to lightning than anything else sticking up in the air, but also no less. I had the unfortunate experience of losing about half of my electronics to a strike a couple years ago and my experience is that a ground will probably save your house, but not protect your electronics. If you get a direct hit, surge protectors won't do much either except burn out at the same time. Their main value is in the insurance they carry. In my case all my old analog units survived, but anything with chips was dead. The ground won't prevent a flash surge of many many thousands of volts, but it will drop the current level so fire is less likely. Chips are fried by voltage in addition to current so that's that; a strike is real bad. The good news is that it took a good number of years before I got hit. The chance of a strike at any one point is very small. If you're really worried, I suggest putting up a lightning rod, close to but separate from your house, with a solid ground connection. If lightning does get close, it might prefer the higher rod.

 

[m_vanmeter]

this applies to any antenna, or piece of metal, projecting into the air above your house. There are two kinds of damage lightning can cause....the direct strike and "induced currents and voltage". Truthfully, there is not alot you can do other than try to mitigate a direct strike...the energies involved are just too great. Proper grounding of your electrical system and grounding for all antennas is the only way to prevent (by draining the static electricity charge that appears to attract lightning), or lessen the effects of a direct strike.

"Induced currents and voltage" happen when a lightning strike is near-by. As the lightning passes by the metal in your house, it "induces the flow of electricity" in the metal and wiring and proper grounding can usually take care of this.

So, if you put up a TV or FM antenna, follow the instructions for running a copper or aluminum (I prefer copper) ground wire from the antenna down to a driven 8' ground rod, avoiding any harsh or 90 degree bends in the wire. Also attach a coaxial grounding block to the ground rod and connect your coax feedline to it before it enters the house. AND, run a bonding wire from your new ground rod (or rods) to the main house electrical ground rod and bond them together (required by NEC - the National Electrical Code) to prevent "ground loop hum" in your a/v equipment.

Please, do not consider a copper cold water pipe as a proper "earth ground". In the good ol'days when all house pipeing was copper or galvanized steel, you could assume it would act as a ground. Today there is far too high a chance there is plastic pipe in the supply run to the house, or at places in the house, to make that assumption any more.

Now....that was a long winded answer to a modest question.

 

[dougg]

Grounding Antenna ......

The Ground Wire is in support of Preventing a Static buildup at the Antenna. A negative Buildup will attract the Positive Buildup in the Air and come to it. If a Direct Hit on the Antenna occurs the Ground is worthless to absorb it! Most Lightning starts at the ground and goes up.
National Electrical Code requires the Antenna Ground to be tied in with the House electrical ground also.
I believe that also will help prevent ground loops.
A lightning Strike with a Outdoor antenna is always something You must accept.

I have this Antenna in My Attic and Pick up Moderate Signal Stations 66 Miles away, clear. Use RG6 Shielded Coax.
http://www.solidsignal.com/prod_display.asp?PROD=SPR6010

This Device coupled into Your Coax and grounded will help the Most with a Strike.
http://www.universal-radio.com/catalog/protect/4640.html

Good Luck with it
Dougg