EMP Protection

[caneman]

Maybe one of you electrical engineers can straighten me out on this.

I read at one time that you could protect something like a C/B or AM/FM or small ham radio by sandwich style packaging.

Radio on the inside - next a box - next a total wrapping of aluminum foil - next another cardboard box.

I'm guessing you'ld have to do that with any antenna also.

Is that correct? Am I missing anything? Would this work for FRS handhelds? etc.

Some communications gear even if it's ears only would be nice to have and things like c/b and FRS are cheap to stick on a shelf with extra protected batteries.

[IndianasFinest]

Not sure what good it would be to even have a cb or radio if an EMP blast hits. It's gonna knock out the entire infrasructure that would be broadcasting.

[rambone]

What you're talking about is called a Faraday Cage.

I think you have the right idea, except instead of foil, you are supposed to use copper mesh screen. Some sources recommend that you tie this cage to ground.

The aluminum foil is for lining the inside of your hat with.

Do a search for "faraday cage" and you will find plenty of info.

[inxs]

Best device (use it myself) that I've found is an old .50 ammo can. Faraday cages are nice but a true cage is more or less calibrated for the event and that would be difficult. The military has done a lot of research and it was mostly inconclusive due to the number of variables. Antenna are not really subject to pulse problems of this sort. EMP is not an easy subject and will not be resolved until one happens. A lot has to do with time / rate of change and electrical length of the subject. Take four years of study and you might begin to get the idea......

[6birds]

here's a good read my brother sent me a few months ago.

AusSurvivalist - EMP Protection

[Beau]

Originally Posted by caneman

Maybe one of you electrical engineers can straighten me out on this.

I read at one time that you could protect something like a C/B or AM/FM or small ham radio by sandwich style packaging.

Radio on the inside - next a box - next a total wrapping of aluminum foil - next another cardboard box.

I'm guessing you'ld have to do that with any antenna also.

Is that correct? Am I missing anything? Would this work for FRS handhelds? etc.

Some communications gear even if it's ears only would be nice to have and things like c/b and FRS are cheap to stick on a shelf with extra protected batteries.

From what i have read this is an example of a poor man's Faraday Cage. I found a couple sites that show you how to make them. It is important to have the box grounded.

For antennas I've read that they need to be disconnected from the radio unit and grounded.

[caneman]

I guess I totally misunderstood. I thought if I had a successfully shielded C/B and my daughter had one also, that they would function to talk between the two of us as soon as the blast was over (hour - day - week), and anyone within normal transmission range could be reached too. FRS would only be a mile or two but better than walking. Maybe 7-12 miles for C/B. 2 Meter I have no idea.

[IndianasFinest]

Originally Posted by caneman

I guess I totally misunderstood. I thought if I had a successfully shielded C/B and my daughter had one also, that they would function to talk between the two of us as soon as the blast was over (hour - day - week), and anyone within normal transmission range could be reached too. FRS would only be a mile or two but better than walking. Maybe 7-12 miles for C/B. 2 Meter I have no idea.

That may be a possibility. I was under the assumption you were hoping to contact say police,EMS or any one else not prepared for the blast. You know what they say about assuming....lol. The thing about EMP that is so scary is we just don't have any real idea what will be effected, and what won't. I don't know if you read the current sticky on EMP, but another member asked about a faraday cage. Microwave ovens will work as a shield from EMP, and can be purchased for next to nothing at yard sales.

[caneman]

I'm guilty of making assumptions too. Mine is that the police either haven't had the money or motivation or knowledgeable guidance to do something like EMP prevention. I've thought communication would basicly come down to citizen to citizen.

[inxs]

You should be able to. There will probably be some interesting propagation for quite a while, but short distance should be doable, more so with FRS than longer wave. EMP decreases with the square of the distance, which wasn't said here before or in the link provided- which is pretty accurate otherwise.