VHF radio is FM which is the modulation of a sine wave carrier so that the
instantaneous frequency differs from the carrier frequency by an amount
proportionate to the instantaneous amplitude of the modulating wave.

Single sidebandband suppressed carrier modulation is a form of amplitude
modulation whereas the carrier frequency and one sideband of the modulated
carrier is suppressed.

For S/N the NBFM (VHF) performance is the same as DSB-AM in the presence of
white noise. The SSB performance is superior to both and to SSB-AM because
all the signal power is is placed into a narrower spectral band than the
former.

SSB detection requires the use of synchronous demodulation, preferably with
phase synchronization, otherwise a Donald Duck type voice appears.

Since you never venture far offshore, dixie cups with strings will provide
more than adequate performance.

RB

"Bobsprit" wrote in message
...

I'm not clear on marine SSB radios. Can someone explain how they differ
from
standard VHF? A friend is now offering me a pretty expensive Icom SSB. I
doubt
I have a need for it, but it's basically free. I may just tell him to sell
it
on ebay. I was thinking of adding a AM/SSB (CB) radio to the boat which
would
be better than the GMRS.
So can someone explain what the marine SSB is? Is it VHF with upper and
lowers?

Thanks in advance...

RB