When Lighning Strikes My Radio Distorts

[D.J.]

Hi everyone,

I was ridding in with my dad last night in his truck. It was storming pretty good last night, very big flashes of lightning.

Everytime Lightning would strike, the car radio would distort. I am sure it's a simple explination, but why did this happen?

Thanks

D.J.

 

[zachtheterrible]

Was it AM or FM? AM is very succeptible to lightning striking. FM would be less, but it could still happen if the lightning was close enough.

The reason for this is that AM stands for Amplitude Modulation. The lightning striking creates a very large voltage/current amplitude on your antenna, and the AM radio picks up this change in amplitude.

An FM radio looks for Frequency modulation. The carrier deviates as different modulation levels are introduced. So the FM radio doesn't respond so much to changes in amplitude because its looking for changes in frequency.

 

[D.J.]

The radio was switched onto an AM station.

So the electrostatic charge in the air caused by the lightning was being picked up by the antenna. Is that right.

Could you explain a little more about the Amplitude Modulation and Frequency Modulation. Not sure I fully understand :?

Thanks

D.J.

 

[mstechca]

If the lightning strikes the antenna of a local station and you are trying to get a station farther away, then I'm assuming the antenna at the local station is now hundreds of feet long for a split second which probably starts the distortion.

OR

The station you are trying to listen to probably has the transmitter turned off.

 

[zachtheterrible]

Lightning, no matter where it strikes (within a certain distance) will cause huge distortion on an AM radio. Its just like turning on a drill or electric motor with an AM radio nearby.

It would be rather hard to go into the theory of AM and FM because it would take a looong time for me to write about it. Search for some info on the net, theres plenty of the basics.

 

[D.J.]

Thanks guys,

It looks like I have a lot of studing to do

Thanks

D.J.

 

[zachtheterrible]

Thanks guys,

It looks like I have a lot of studing to do

Thanks

D.J.

Yup. Although if you just want to know the basics of radio, it is very simple, so simple in fact that I think howstuffworks.com has a tutorial on FM and AM

 

[D.J.]

Ok cool I'll start my search their.

 

[Someone Electro]

Yea lighting creates a lot of difrent radio freqencys.

If its close enugh it can ever disort TVs that are on cable.

There is no AM radio stations here.Only about 3 weak ones that are crap.

TVs and comuter monitors also make interference in the AM band. (Try having one close to a screen and then thurnthe screen off,It wont make noise anymore)

 

[D.J.]

"TVs and comuter monitors also make interference in the AM band. (Try having one close to a screen and then thurnthe screen off,It wont make noise anymore)"

Oh, my sister was asking why when she turning her monitor on her radio would get distroted. Her big monitor sits right next to her radio.

 

[Someone Electro]

I think its the flyback transformer making that.Its an transformer that is driven at about 20-30 kHz to make about 20 000 V that is nedded for the electron gun.

We just had an huge lightning storm today.It once got so close the pule was picked up by my computer speakers.

 

[zachtheterrible]

It once got so close the pule was picked up by my computer speakers.

Thats pretty scary!!

There was once a lightning storm, and even when my computer was off, somehow the lightning traveled down the phone line and knocked out my modem

 

[Someone Electro]

2 weaks ago it fryed my dads mother board.And after a weak the hard drive stoped working (It was damaged from the lighting)

His PC was off.At that time i was using my PC and nothing hapend to it! Now he instaled an overvoltage protection on the phone line and the power for the PC and monitor.

That lightning yestaerday was prety loud too.Just sudenly i heard an scratch in my PC speakers and a big flash than an realy LOUD bang.Yea it scared me becose it was just sudenly.

Oh an the delay of the bang from the flash was somewhat less than a second.And how fast dose the sound travel agen? (yea il tra to figure aout how close it was)