Posted: 10/7/2007 5:34:38 PM EDT
| Can anyone revisit the thread where the guy made a self contained mobile HAM unit in a tackle box!..I thought that was greatest thing I'd seen in awhile!! |
| If your rig is attached to outside power lines or an antenna it will likely get fried in case of a big EMP event. http://www.survivalblog.com/2006/09/letter_re_expedient_faraday_ca_1.html Here is a link on making Faraday cages from ammo cans and is pretty informative on the subject. A great deal of what would happen depends on the type of EMP detonation(how high above the earth and thus how large the footprint) and a thousand other factors and the experts are not even sure about all of the effects and I do not pretend to be an expert. My studies do seem to indicate that being tied to outside power lines would be by far the greatest risk. If you are worried about EMP then power your radios from large batteries that are charged by a few solar panels and store radios that are not in use in an old micro-wave oven that has been WELL grounded.The Faraday principle is what keeps the energy inside of a micro-wave so they are in effect perfect Faraday cages. You could also use one of the shielded ammo boxes described in the link above. There is a lot of bad information out there on the subject and I am still trying to learn. On a recent tour of the TennTec factory I studied their in house Faraday cage used to set up some of their most sensitive government agency receivers and it is not complicated. The cage has to be surrounded by metal,in this case a fine mesh hardware cloth over a 2x4 structure and a HUGE ground wire. Completly surrounded my ELECTRICALY connected metal on all six sides and grounded by the shortest path with the largest possible wire seems to be the cure for our EMP worries.73's BallGroundBoy |
a lot of the information in that link is incorrect. for example,
advances over the last 10-20 years in semiconductor design and manufacturing techniques have drastically improved resistance to ESD (static) and induced noise. moreover,
these types of applicances do not fit the description of a faraday cage; namely, there is no RF integrity. the insulating seals at the doors etc, and the poor bonding of adjacent surfaces will guarantee RF leakage. don't believe me? get a portable radio (ham, weather, etc), turn it up loud, and put it in your refrigerator. i just did this with my VX170 (a 2M ham radio with a very sensitive receiver) and i can hear NOAA weather on 162.550MHz just fine with the refrigerator door shut. more info is here, ar15.com/forums/topic.html?b=10&f=17&t=599861 ar-jedi |
ps: click here, tacked Ham 101 thread --> http://ar15.com/forums/topic.html?b=10&f=22&t=604477 and scroll down to the section titled "communications bug-out-boxes / emergency radios" -- there are a lot of links in that post, one of which might contain the box you are looking for. ar-jedi |
