The United States has 4 sets of frequencies under the category of "Personal Radio Services" which any one can use with certain restrictions on power output, antenna height and location. There are three others (MICS, WMTS and GMRS) under this category however they require that you are either a medical care facility or have special permissions or certification to use.
No FCC License Required Frequency Bands:
- CB (26 & 27 Mhz) HF 4W AM Carrier, 12 W PEP Single Side Band
- MURS (151 & 154 Mhz) VHF FM 2 W
- LPRS ( 216-217 MHz) UHF FM 100mW
- FRS(462-467 Mhz) UHF FM 500 mW
- MICS - Health Care Services - (402-205 Mhz) FM UHF
- WMTS - Health Care Services - (1429 to 1432 MHz)-(1395 to 1400 MHz)-(1429 to 1432 MHz) - FM UHF
- GMRS (462-467) - Certification required - FM -UHF 5W+
I also found that CB radio used to be the old 11 meter HF amateur radio band. The nice thing about HF radio is that its range is greater than line of sight due to atmospheric bounce. The FCC limits the power on most of these frequencies because in order to amplify a signal they have to take great care in not creating interference on other frequencies.
GMRS radios are readily available but require a license to use. The GMRS radio license allows for the use of repeaters and higher output. FRS and GMRS share several frequencies, the difference is that GMRS radios are allowed to broadcast at 5W instead of just 500mW.
You can find FRS/GMRS radios just about any where for under 20$, MURS radios range from
50$ to 100$, CB's range between 40$ to 100$, I couldn't find anyone selling LPRS.
Links:
CSG, Computer Support Group, Inc. and CSGNetwork.Com , "Glossary" (Accessed Dec 2009)
http://www.csgnetwork.com/
http://www.csgnetwork.com/gmrsfreqtable.html
http://www.csgnetwork.com/frsfreqtable.html
http://www.csgnetwork.com/mursfreqtable.html
http://www.csgnetwork.com/cbradiofreq.html
http://www.csgnetwork.com/lprsfreqtable.html
http://www.csgnetwork.com/micsfreqtable.html
Federal Communications Commission. " Personal Radio Services" (Accessed Dec 2009)
http://wireless.fcc.gov/services/index.htm?job=service_home&id=personal_radio
See also:
HAM it up!
http://www.h-i-r.net/2009/04/ham-it-up.html
Introduction to Proximity Cards
http://www.h-i-r.net/2008/09/introduction-to-proximity-cards.html
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