On Thu, 1 Dec 2005 22:39:01 -0800, "William Andersen"
wrote:

Why would I want a second MMSI for a second radio?

You don't.

I'm going to add a second radio with DSC capability and wonder if there's
any reason to get another MMSI for the second radio.

No.

Since both radios are going to be on the same boat, it seems to me that I
should program the same MMSI in both radios. If one radio fails the other
will be ready to go.

Correct - the MMSI belongs to the boat, not the radio. You might
think of the MMSI as a modern version of the call signs we used to
have - one call sign covered all radio equipment associated with the
vessel.

In normal operation, one radio will be primarily used with a direction
finder; the new radio will be the primary communications radio and will also
be connected to my chart plotter to display vessels transmitting DSC
information.

To avoid confusion and multiple alarms, you may want to disable DSC
reception on the secondary radio. On the SC-101 radios I've looked
at, the Channel 70 scanning can be disabled, which will disable the
DSC reception. On my Class D radio, I can only disable the automatic
channel switching.


--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq