GMRS vs Marine VHF
 

Can anyone tell me what the difference in performance would be between
(handhelds): a 5w GMRS vs. a 5w Marine VHF in mountain terrain
(ignoring legalities.)


Your comments are appreciated.

John wrote:
Can anyone tell me what the difference in performance would be between
(handhelds): a 5w GMRS vs. a 5w Marine VHF in mountain terrain
(ignoring legalities.)

Performance? Do you mean range? If so, the answer is: It depends. The
GMRS radios operate on UHF (450 Mhz band) and the marine radios operate
on VHF (150 Mhz band). The path loss on line of sight communications
will be greater on UHF, but improved receiver sensitivity and
easier-to-achieve antenna gain can offset that. The specifications on
the individual receivers in question are probably more important
determinates of range.

Worry more about the legaliities and less about performance and you'll
be OK.

In article . com, "John" wrote:
Can anyone tell me what the difference in performance would be between
(handhelds): a 5w GMRS vs. a 5w Marine VHF in mountain terrain
(ignoring legalities.)


Your comments are appreciated.


Aside from better line of sight performance of the GMRS and Marine units, a CB
will work better over hills.

greg

On Fri, 26 Aug 2005 13:15:39 GMT, (GregS) wrote:

In article . com, "John" wrote:
Can anyone tell me what the difference in performance would be between
(handhelds): a 5w GMRS vs. a 5w Marine VHF in mountain terrain
(ignoring legalities.)


Your comments are appreciated.


Aside from better line of sight performance of the GMRS and Marine units, a CB
will work better over hills.

greg

Not necessarily. As part of setting up a CERT organization in our
housing development, we tested CB, FRS and GMRS hand-helds. The CB's
and GMRS were 5-watt. Our area contains about 1,600 homes, built
around a golf course, with many rolling hills. The goal was to be
able to reach from one end of the development to another. The FRS
were completely useless. So were the CB's. The GMRS units weren't
great, but they did provide acceptable communication. MURS wasn't
available at that time. That's what I would look at in this
application. The problem with CB's is the antenna. A quarter-wave on
the CB band is 9-feet! A quarter-wave on GMRS is about 6-inches.
Much easier to have an efficient HT antenna on the GMRS band.

I wouldn't even consider using marine radios on land. Do you really
want the FCC AND the Coast Guard on your tail? They take use of these
radios very seriously.

Dick