Wifi antenna and lightning

[JF Massicotte]

I have a question

Are car antennas properly grounded on the car? Is there any risk if a ligntning would hit antenna? Are those lingtning stopers helpful or should I simply get antenna back in car when too close?

Thank you very much.

 

[Billy Griffin]

Not an expert here, but it's probably err on the side of safety. There's no way that I can think of to 100% guarantee your vehicle cannot get struck by lightning. At the same time, I wouldn't think of your antenna as increasing the risk.

 

[David Drummond]

In 23 years of being out around storms with all manner of antennas, I have had one hit with lightning exactly once. Way back in the 80s I had a pickup with dual whips. The old highway patrol style huge long whips. To make it worse they were mounted on the top edge of the bed behind the cab on either side. I was asking for it. Melted the antenna about half way down and fried the insulation off every electrical wire in the vehicle. We were 15 feet from a power pole that was taller than the antennas.

That is the one and only time in all those years I it's every happened. Needless to say though, I never used those long whips again.

 

[David Wolfson]

Search on "lightning antenna" and you'll find a number of discussion threads about this.

But the bottom line is that lightning can indeed strike an antenna. If it does the bolt will almost certainly find its way around the outside of the car and to earth because of the skin effect. Unless the leads have truly superb lightning suppression, enough high voltage will find its way to the front ends of your radios to fry them good. If you happen to be holding a mike, etc., enough high voltage will find its way to you to give you a good jolt, but probably not injure you severely. Note the probably....

Because lightning looks like (very high power!) rf, multiple coiling or cleating of a feed line may limit the degree to which the spike passes that high-impedence point. Note the may....

However, since getting struck while in the process of taking down antennas is a truly once-in-a-lifetime experience, and since it's likely you're probably at risk by the time you decide to take them down, it's probably best to stay safely in the car. If the rare event occurs and you're struck, then it becomes an adventure to tell your loved ones and friends about for many, many years to come.

 

[JF Massicotte]

Thank you very much for your answers guys.

In fact I was more afraid of frying my brand new 2000$ laptop than having problems with anything else. If a lightning strikes my car I know I am in safety inside of it, but if it strikes the wifi antenna, this one is directly connected to the poor defenceless laptop and bring it into the car where my partners and I are.

Think I'll just disconnect the card from the antenna when too close to storms.

Will be my first year chasing with any other equipment than my cellphone.

 

[Ryan McGinnis]

A long while back, I picked the brain of some electrical whiz on Usenet (the guy used to do radio tower lightning protection installs). The long and short of it is this:

If you have a mag-mount antenna and the antenna is struck, there's a good chance that the bolt will enter the car and ruin your day.

If you have a permanent body mount antenna and the antenna is grounded at the entrypoint to the car body, you're probably okay. If you use a lightning resistor inline at the grounding point, you're much safer.

You're never 100% safe in a car, as there is nothing stopping the bolt from entering through the window or moonroof (if you have one), though it's rare.

If you do a search, you'll find a more detailed thread I posted about this back in the Archives somewhere.

 

[Gene Moore]

We've discussed this on WXChase from time to time. One issue I've brought up is the corona discharge that builds up on antennas under a storm. I think the worst place (potential) is under the anvil canopy of a supercell. If it gets strong enough it will hunt for a place to discharge, I've had my hand shocked numb more than once over the years. Bill Tabor saw me light up the inside of the vehicle once in the Oklahoma Panhandle .

Also it can trash electronics, those circuits can't take that kind of voltage. It's been known to ruin scanners and cell phones so consider that in your grounding efforts. A mag-mount just won't get the job done. For inside the vehicle you can make an alligator clip grounded to the frame (bolt under the car seat) and clamp it to the outside of your connectors. This will bleed off the excess voltage. The amateur radio folks here will have other suggestions I'm sure.

Gene Moore