FRS/GMRS use after an EMP

[crewcabrob]

Hi all,

First time poster on the site. I'm looking for specific information to protect my FRS/GMRS radios from an EMP or other natural occuring event that is similar. I have been building and testing several Faraday cages to block out the over powering RF/radiative signals caused by these types of events, but none of them have kept my FRS/GMRS radios from reciving signals. This worries me that I may not have protection for ANY of my electonic devices.

My Faraday cages will block out cellular signals consistently. But every time I think I have one done, I test it with my radios and none pass the test. I wonder if the GMRS/FRS radios frequency is so tight it can pass right through my Faraday cages.

I understand that an EMP or similar event will give off large amounts of microwave radiation which is in a totaly different part of the band/specturm. What I'm not sure of, is how much bleed over to other parts of the band/spectrum such an event will have.

Does anyone have any suggestions or insight on hardening a tactial solution for such an event? My cages are a serries of all meatal containers with non-conductive materials coating the inside. I have even added smaller all metal containers to protect smaller more fragile electonics within the larger containers and yet my FRS/GMRS radios transmit right through.

I'm not planning on using these radios after such an event for anything more than communication with my family which is local. I'm not interested in long range communication or communication to call for emergency services which will most likely not be available.

Has anyone covered this before or have any specific advise for me reguarding my questions?

Thanks,

Rob

[prcguy]

Besides Gamma Rays and other ionizing radiation, voltage induced into circuit board traces and components would be the major thing you want to prevent.

When a nuke goes off, especially airborne, it can disrupt the earths magnetic field and anything conductive in the near vicinity becomes the armature windings of an alternator with the earths giant magnetic field rapidly moving through it.

This can produce thousands of volts in wiring and circuit boards but radios and such can be shielded from damage with a box using a combination of steel (or MU metal) and copper.

A Google search should find you some examples of shielded enclosures for surviving a big EMP event.
prcguy

[K9WG]

I think that if you are close enough to an EMP to damage your equipment you won't be around to worry about it....

[Thayne]

Originally Posted by K9WG

I think that if you are close enough to an EMP to damage your equipment you won't be around to worry about it....

I think ya got that right--

I have a brother in law that just bought an old jeep with no solid state anything it it for that very reason

[gewecke]

......vaccum tube frequency agile gear with extra tubes and caps will survive, but you on the other hand?

73,
n9zas

[LtDoc]

Got any lead foil?
- 'Doc

[KC2OBW]

This was brought up in a club meeting once, some one suggested that we protect our repeaters from EMP'S, the reply to that was "if a EMP goes off who are we going to talk to?"

[jhooten]

A nuclear detonation is not the only source of an EMP. A CME from the sun can cause EMP like effects.

A deliberate attack intended to cause a disruption to comm/elec systems will be a by a HEMP (High altitude Electromagnetic Pulse) device. A large nuclear weapon with the blast effects tailored to cause the maximum emission of electromagnetic waves instead of the normal destructive heat and blast that will be triggered at a high altitude to cause the most wide spread disruption while causing minimum damage to structures and people, and almost no fall out. If you destroy it or contaminate you cannot occupy it.

[thomast77]

I saw a video on youtube where a galvanized trash can was used. Line it on the inside with cardboard to prevent accidental contact with the metal. Faraday Cage: Garbage Can I got one myself and put some backup radios in it. I read an article that recommended a double faraday so I also wrapped those radios in the box with aluminum foil. I also made faraday pouches for my scanners and laptop so if I see it coming I can slip them in the protective sleeve. DIY EMP pouch No grounding is required. Some people will disagree with this but the military has EMP proof Aircraft such as Air Force one. and they don't have a ground. I think the trick is double shielding. Hope this helps or gives you some ideas.

[n5ims]

Critical military communication systems have some specialized tube type equipment for communicating after an EMP attack. Their testing (and who else can accurately test EMP survival) shows that properly designed tube type equipment will provide the best results following a damaging EMP event, especially when this equipment is off-line and properly isolated as their back-up equipment proceedures specify.

[thomast77]

Originally Posted by n5ims

Critical military communication systems have some specialized tube type equipment for communicating after an EMP attack. Their testing (and who else can accurately test EMP survival) shows that properly designed tube type equipment will provide the best results following a damaging EMP event, especially when this equipment is off-line and properly isolated as their back-up equipment proceedures specify.

What about cockpit/Airplane electronics systems?

[wuzafuzz]

Originally Posted by thomast77

What about cockpit/Airplane electronics systems?

That's when we'll find out how many glider pilots work for the airlines. Unless fly by wire turns into fry by wire.

[Thunderknight]

Originally Posted by crewcabrob

My Faraday cages will block out cellular signals consistently. But every time I think I have one done, I test it with my radios and none pass the test. I wonder if the GMRS/FRS radios frequency is so tight it can pass right through my Faraday cages.

What you are probably getting is attenuation of signals in your cage, but not enough to block the nearby GMRS radio. The cellular signal is weaker to the inside of the box to start with than your nearby GMRS radio. (The further you get from a transmitter, the less power is received.) So basically your nearby GMRS radio is putting a higher relative power inside your faraday cage than the cell phone's signal inside the cage.

Actually cellular wavelengths are shorter than FRS or GMRS frequencies.

(the above is assuming you are testing from a second nearby GMRS radio).

Have you made sure to seal ALL seams, lids, etc in your containers? They need to be electrically sealed (e.g. soldered).
Large faraday cages often have special door frames with copper strips that sort of meld together to make a tight seal.

[crewcabrob]

Hi Guys,

Thanks for all of the responses on my issue.

I do have the galvanized can as the primary cage. I have wrapped items within the cage with foil or put them in the tin boxes that cookies com in during the holidays. Each layer has been insolated with a nonconductive material so the electonic items are not in contact with the foil or tin of the box. The galvanized can is lined with cardboard so nothing inside the can comes in contact with the exterior. I am actually thinking of purchasing one of the larger galvanized cans to put 1 or 2 of the smaller cans inside. This would be the primary outside barrier at this point unless I can source a large safe to put all of the layers in.

For all of the responses that want to make lite of the posibility that such an event may happen, or that survival is a slim chance, I really hope that you rethink the many senarios that can cause a situation like an EMP or loss of the grid for an extended period of time. I guess I was a bit suprised that I got some of those types of responses on a forum based on emergency/secondary communication. I would have assumed that the issue would have been covered many times before I showed up. I'm not saying anyone is wrong or that opinions are wrong, I just want everyone to have the information and then make an informed judgement on what they want to believe.

I appreciate the information pointed out about the proximity of the GMRS transmitter to the cage. For me, I wanted to test as much power as I had available. I really don't know what type/amount of power will be behind an EMP type of event, I suspect it will pack more of a punch than my radio can put out, so it makes me worried for survival of the electronics within the cage. Soldering the joint of my cage is not practial, so I may need to at least clean the seam of the can where the lid/body contact is made.

I will look at other materials to use for protection. I hear copper mesh would be great. Lead foil would be nice, but I'm not sure where to source something like that. If nothing else, I will try to tripple protect my more sensative items that will be kept for long term storage.

Any other suggestions or links that anyone thinks would be useful for this issue?

Thanks again,

Rob

[crewcabrob]

Originally Posted by KC2OBW

This was brought up in a club meeting once, some one suggested that we protect our repeaters from EMP'S, the reply to that was "if a EMP goes off who are we going to talk to?"

Hi,

I agree that there might not be anyone to talk to like emergency services or such. I want mine for personal use after an EMP or similar event. My son and I have already started making plans for after such an event. As part of our "after" plans, we want to be able to communicate even if it is close range. My radios are all Motorola radios with at least a 25 mile range listed. I have been able to test them up to 10 miles and that is more than sufficent for my needs. My wife and daughters are oblivious to the preparations or conditions after such an event might take place.

I'm not only protecting my radios, but other sensitive equiptment too. I have Steripens, chargers and LED flashlights. I have even purchased some portable solar equipment from Goal Zero to use for charging.

I have other contigencies if none of my electronics work after such an event, but protecting some of these things could sure make the difference between survive and thrive if the grid is downfor an extended period of time.

Rob

[jvdet]

tubes?1 save those tubes, and older cars may still work, after the EMP, and if you watch NATGEO channel or was it EXplorer anyway they just did a story today on a MCE - Mass Coronal Ejection - its comes from the sun and how it can and has in the past fried the power grid; which happen in Canada some years ago , its a question of when ... oh there was a MCE a few weeks ago ....but the earth magnetic field protected us so what do we do now ...

[crewcabrob]

A MCE is a similar situation, so preparing for one is like preping for both. I will have to check out NATGEO to see the show.

Thanks,

Rob

[crewcabrob]

Hi guys,

So, I went and bought a larger steel galvanized can for more protection. I now have a large can, lined with non-conductive material and then a smaller can inside that lined with non-conductive material and then items individually wrapped in aluminum foil. None of the aluminum wrappings are touching each other, sso I hope I finally have a few thing protected.

Does anyone have any other ideas? I alreay have them in the lowest part of my home. I sure wish I had a natural cave of some sort I could further get them underground.

Rob

[nayr]

they have to be grounded, this weekend I am pounding a few grounding rods down in the bottom of each basement window wells and bonding em all together with the main power ground. The big metal server racks that house all my equipment has copper grounding bars on there way.. I need to find a big copper strap to run from my racks to the grounding system... a good lightning protection system is the first step in EMP hardening, if you cant dump massive voltages to earth then you dont stand a chance.

The whole, who will you talk to thing is kinda tired.. most systems are redundant and already some of the best hardened systems with extensive protection, redundancy, and backup power... if every one of those facilities were destroyed then your foil covered box in your basement is also toast.

-R

[gewecke]

Originally Posted by crewcabrob

Hi Guys,

Thanks for all of the responses on my issue.

I do have the galvanized can as the primary cage. I have wrapped items within the cage with foil or put them in the tin boxes that cookies com in during the holidays. Each layer has been insolated with a nonconductive material so the electonic items are not in contact with the foil or tin of the box. The galvanized can is lined with cardboard so nothing inside the can comes in contact with the exterior. I am actually thinking of purchasing one of the larger galvanized cans to put 1 or 2 of the smaller cans inside. This would be the primary outside barrier at this point unless I can source a large safe to put all of the layers in.

For all of the responses that want to make lite of the posibility that such an event may happen, or that survival is a slim chance, I really hope that you rethink the many senarios that can cause a situation like an EMP or loss of the grid for an extended period of time. I guess I was a bit suprised that I got some of those types of responses on a forum based on emergency/secondary communication. I would have assumed that the issue would have been covered many times before I showed up. I'm not saying anyone is wrong or that opinions are wrong, I just want everyone to have the information and then make an informed judgement on what they want to believe.

I appreciate the information pointed out about the proximity of the GMRS transmitter to the cage. For me, I wanted to test as much power as I had available. I really don't know what type/amount of power will be behind an EMP type of event, I suspect it will pack more of a punch than my radio can put out, so it makes me worried for survival of the electronics within the cage. Soldering the joint of my cage is not practial, so I may need to at least clean the seam of the can where the lid/body contact is made.

I will look at other materials to use for protection. I hear copper mesh would be great. Lead foil would be nice, but I'm not sure where to source something like that. If nothing else, I will try to tripple protect my more sensative items that will be kept for long term storage.

Any other suggestions or links that anyone thinks would be useful for this issue?

Thanks again,

Rob

If a EMP charge is detonated, you are going to have far more important things to worry about than your radios!
Unless you can pack them in a lead container, basically they will become junk.
Have you been watching post- apocalyptic movies?

73,
n9zas