You haven't said what frequencies your radios use. I assume you have PMR446:
http://en.wikipedia.org/wiki/PMR446
In the United States, 446 MHz is the national simplex calling frequency for the 70 cm band allocated to amateur radio. If you operate on amateur radio frequencies (also called ham radio), you may be interfering with hams local to the Gerlach area who use amateur radio frequencies for real-life communications, given there are often no phones anywhere around Black Rock Playa. Please, please, please be sure you don't interfere with them. They will legitimately complain to the FCC about Burners causing harmful interference and give BMOrg another set of problems to deal with. There is a significant Burner/ham presence at the Burn, and we don't want to lose our operating privileges while we're there.
FRS and GMRS use 'interstitial' frequencies, not the 400-500MHz band. See the chart here:
http://wiki.radioreference.com/index.ph ... nnel_chart
Ignore the channel numbers and read the frequency column and note whether that frequency is used only in GMRS, only in FRS, and in both. If you do not have a GMRS license, you are not allowed to use GMRS frequencies; FRS is license-free. GMRS license requirements are on the Federal Communication Commission's page here:
http://www.fcc.gov/encyclopedia/general ... rvice-gmrs
You need to know what frequencies your radios are operating on and to use them only on the FRS frequencies, if possible. You should also check to see if your radios can operated on the five MURS frequencies:
http://www.fcc.gov/encyclopedia/multi-u ... ice-murs-0
MURS is also license-free, and you can use MURS radios on four of the five at the Burn, with one of the frequencies being reserved for emergency calls for aid. If you can use MURS frequencies, let me know, and I'll find that emergency frequency so you can stay off that channel.
If you find you can't get your radios to operate on the interstitial frequencies alloted to FRS and MURS, you'll find that FRS radios here in the states are cheap. It may be that you can wait and buy them in Reno when you arrive, along with batteries, of course. :->
You can do a web search and find Reno sellers and make arrangements to buy your FRS radios and have them held for you to pick up when you arrive. I'm sure you'll make lots of new friends on FRS while you're there.