Dumb DSC Question - Distress without MMSI

[fairbank56]

Well, I just tested an Icom M502 (circa 2000) and it will not transmit a distress call without an ID number programmed and I just happen to have an Icom M127 with DSC board (circa 1997) (first Icom with DSC I believe) and it also must have ID to transmit. A number must be programmed as the ID is a required field in the data stream. I think it's unlikely but there may very well be some radio's out there that have a default ID already programmed into them. I do remember an AIS problem where a certain manufacturer (Nauticast?) had a default ID in an early class A transponder. Iv'e just purused multiple operating manuals from various models and they all indicate that an ID must be programmed for transmitting DSC and that if you press the red button without an ID programmed, it will display NO MMSI and sound an error beep. For those who want to claim that a VHF DSC radio will transmit a distress message without a programmed ID, how do you know that? The only way to know for sure is to test it. Iv'e tested Icoms, Standards and Furuno's and they will not work without ID.

Here's a Coast Guard pamphlet that clearly states:

The DSC radio “distress alert” transmit features
will not work without the MMSI number properly

programmed into the radio

http://www.uscg.mil/hq/cg5/cg534/sar...SIpamphlet.pdf

Eric

[HappyMdRSailor]

Originally Posted by CaptTom

Ironically, I had another MMSI issue come up shortly after I wrote this. I went to program my new MMSI number into the radio I'd originally installed in my last boat. I did all the steps right, but halfway through, the CG did a broadcast on channel 16. The display changed and the half-updated MMSI number was stored. That was my last chance. I have an e-mail in to the vendor to see if they'll take pity on me, or will charge me $60 to reset it.

Moral of the story: put the radio on some odd-ball channel, or disconnect the antenna, before changing your MMSI!

Wow... That's a handy tidbit of information right there!!!