|Lightning protection on a satellite dish?|
| 5:41 pm on May 9, 2006 (gmt 0)|
I've got a new satellite dish on top of my house for high speed internet. I live in a very lightning prone area, in a mobile home. I've had two close lightning strikes in five years, including one that flashed into the house and nuked some electronics.
The dish is grounded, though I may put a bigger ground rod on it. Is there anything else I can do to protect it -- and the equipment it's plugged into, and the house it's sitting on? :)
| 11:27 am on May 10, 2006 (gmt 0)|
In addition to grounding the dish itself, you need to ground the RG6 cable going from the dish to your computer or router. You can buy a special connector that accepts two male RG6 connectors, and has a ground screw. I believe it's recommended that you create a separate grounding wire from that connector, and not use the same one you are using to ground the dish itself.
| 9:04 pm on May 10, 2006 (gmt 0)|
Sounds like a great place to have a lightning rod or two installed. These should each have their own ground, away from the anode rod by the meter or the water pipe. These will offer a cone-shaped area of protection below.
Aside from commercial surge protectors, I'd be inclined to make my own home-brew arrestor too. I read of a person having problems with faxes getting blown by phone-line surges, even with a commercial lightning arrestor. He added fractional-amp fuses inline with the phone. After a lightning storm, he found the fuses blown, but after replacement the fax worked. No word on how well paired high-bandwidth applications handle a modification like this, but this should inspire the tinkerers among us.
| 10:11 pm on May 10, 2006 (gmt 0)|
|You can buy a special connector that accepts two male RG6 connectors, and has a ground screw. |
Actually, what you want is a "lightning arrestor". It may just look like a connector with a ground screw, but there is (or should be) a chamber inside with an airgap between the signal line and the ground. This allows any surge to cross the gap to ground.
I assume a wide variety of these are available for satellite dishes. I don't have a satellite dish, but I do have shortwave and VHF/UHF antennas. I use an Alpha Delta "arc-plug" type arrestor. (The arc-plug is replacable in case of a hit.) These are expensive ($60) but are the Cadillac of lightning arrestors. You will lose .5db at 3gHz , .2@2gHz (probably fine - not sure what the frequency range of the convertor output on your dish is) and only come with "N" connectors, so you would need plug adapters - probably 2 female F to male N - or else install N connectors on your cable.
(It also can come with "UHF" connectors. You DON'T want those, as they are a low-frequency connector design.