"Robert11" wrote in message
. ..
Hello:

New at this:

Regarding the Coast Guard S&R frequency of 237.9 that I recently read
about:

Is this the primary S&R freq used most everywhere ?
Is it used for air to ground and also ground to air usage by the C.G. ?

Is it an AM mode

Are all freq's between 225.000 and 399.950 (always) AM ?

NO.

AM tends to predominate,but
this area is dominated by the US military, and there are all sorts of
strange RF using things in here.
Satellites, Air-ground coordination links, air-air comms, "squad radios"
( a sort of army FRS) are near the upper end of this band, some ground based
anti-personnel radars..

And just too make it more confusing, the DOD has been recently changing its
band plans ( which were never too strict to begin with) for this band.


Thanks,
B.