Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 19-06-2013, 10:33   #16
Registered User
 
S/V Alchemy's Avatar

Join Date: May 2008
Location: Toronto
Boat: Custom 41' Steel Pilothouse Cutter
Posts: 4,577
Re: Another dumb DSC VHF question

Quote:
Originally Posted by AD 2 View Post
Thanks. I've been skimming the manual, and will go into it more when I get back down to the boat tomorrow. It's a real eye closer, though...

Whereabouts in Toronto are you? We're at MMC.
Do you mean Mimico Cruisng Club (MCC)? I was at Etobicoke for a couple of seasons as my boat partner of the time was there. My main boat is at National YC. You can see it at the link in my signature block below.

The reason to use MMSI and DSC is pretty straightforward (you need a Radio Operator's Certificate with DSC endorsement, by the way...it's a good class).

Besides the MMSI number referencing your boat, the "digital" side of things means greater range than sometimes dodgy "analog" voice transmission can cope with. Also, ch. 70 DSC calling is more secure when you have boats calling MMSI to MMSI when compared to Ch. 16 calling. Lastly, a DSC Mayday can be easier to relay to shore if you (for instance) are dismasted and just have a handheld with a DSC button. It's well worth the time invested, in my view, to activate it.

Throw in the AIS factor, however, and it becomes part of a "total awareness package" wherein the RADAR shows you the shore line on foggy nights and the AIS shows you the ship traffic. Anything neither shore nor ship is probably a non-AIS equipped boat. Call them with their MMSI and you can tell them to hold their course and from which direction you'll be making a close approach. It's as if the blind had talking white canes.
__________________

__________________
Can't sleep? Read www.alchemy2009.blogspot.com for fast relief. Can't read? Avoid www.volumesofsalt.blogspot.com, because it's just personal reviews of sea books.
S/V Alchemy is offline   Reply With Quote
Old 24-06-2013, 06:22   #17
Registered User

Join Date: Jun 2012
Location: Toronto ON
Boat: Morgan 33 O/I
Posts: 30
Images: 2
Re: Another Dumb DSC VHF Question

Yes we are at Mimico, only a friendship gate away from EYC. I just picked up the radio to replace an earlier non DSC model that was in the boat when we got it last year. I'm especially enamoured of the e-distress feature, and am looking forward to checking out the quality of the digital voicestream. I'm just waiting for the Ministry to send out the MMSI. And down the road, AIS is definitely on the radar. As they say.

I was checking out your blog – very nicely written. Alchemy’s a sweet looking boat. It looks like we have similar outlooks on life in general, particularly in the reduce/reuse/recycle department, and in not underestimating the value of the lo/no technologies of our forebears in the rush to embrace the shimmering gadgetry of the future. We put up substantial quantities of food in season, munching it leisurely for the rest of the year, and I very much enjoy the fermentation method of barley preservation, infusing an antibacterial agent (say, hops) and bottling the result under slight CO2 pressure. A skill’s no less of a skill for being ancient. As Isaac Newton may have said had it occurred to him, if we have trains, planes and automobiles (also boats), it is because we are driving over the heads of people who traversed continents on their feet.

We took our first baby boat steps this weekend, a stately procession of 12nm all the way to Oakville, and the radio was fine. Also our first baby radio steps, come to think of it. You are way further along your sailing trajectory than we are - who isn't? - so I very much appreciate the clarity of your kind and sagely advice.


Billy
__________________

__________________
AD 2 is offline   Reply With Quote
Old 24-06-2013, 06:38   #18
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: Another Dumb DSC VHF Question

Quote:
Also, ch. 70 DSC calling is more secure when you have boats calling MMSI to MMSI when compared to Ch. 16 calling. Lastly, a DSC Mayday can be easier to relay to shore if you (for instance) are dismasted and just have a handheld with a DSC button. It's well worth the time invested, in my view, to activate it.
Not really any security at all, the voice call is still as normal and can be detected by any scanning VHF.
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 24-06-2013, 07:58   #19
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Seattle
Boat: Cal 40
Posts: 2,401
Images: 7
Re: Another Dumb DSC VHF Question

Quote:
Originally Posted by AD 2 View Post
Yes we are at Mimico, only a friendship gate away from EYC. I just picked up the radio to replace an earlier non DSC model that was in the boat when we got it last year. I'm especially enamoured of the e-distress feature, and am looking forward to checking out the quality of the digital voicestream.
Billy
Only thing digital is channel 70.
Pushing the distress button sends your MMSI number and GPS location digitally. When the coast guard acknowledges your signal the radio automatically is switched to channel 16, where you talk which them just as you used to on an analog open to everyone channel.

You can place a call to another boat using their MMSI digitally. Only the boat being called announces your desire to talk. Their radio will change to the analog working channel that you have selected when they acknowledge. You then talk on a normal analog open to everyone channel.

There are other functions such as ask for your buddies GPS location which is sent to your radio and displayed.

John

Can You Hear M e?
__________________
cal40john is offline   Reply With Quote
Old 24-06-2013, 08:31   #20
Registered User
 
jeremiason's Avatar

Join Date: Oct 2010
Location: Punta Gorda, Florida
Boat: Sea Ray 270
Posts: 1,427
Images: 2
Send a message via ICQ to jeremiason Send a message via Yahoo to jeremiason Send a message via Skype™ to jeremiason
Re: Another Dumb DSC VHF Question

DSC is great when you have multiple boats cruising together or even racing. You can DSC them and switch them all to a working channel at once by selecting preprogram DSC numbers.

Another great feature is the ACK function, which allows you to ask for a status check from buddy boats... If they ACK, you know everything is OK.

The Request Position Report, in conjunction with a chart plotter is a very cool function. If you radio is connected to NEMA, the position will appear on most chart plotters as a waypoint. This is good when searching for a buddy boat in a crowded anchorage or see where they are if you are cruising.

DSC is a great tool!
__________________
Tom Jeremiason
Punta Gorda, Florida

jeremiason is offline   Reply With Quote
Old 24-06-2013, 15:07   #21
Registered User

Join Date: Apr 2007
Posts: 718
Re: Another dumb DSC VHF question

Quote:
Originally Posted by goboatingnow View Post
to prevent MMSI spoofing, thats why , ITU says 3 goes max, some have less.
The latest ITU DSC technical spec that I have doesn't give a number, it simply states "Once stored, it should not be possible for the user to change the MMSI number without advise from the manuafacturer."

Eric
__________________
fairbank56 is offline   Reply With Quote
Old 24-06-2013, 15:17   #22
Registered User

Join Date: Apr 2007
Posts: 718
Re: Another dumb DSC VHF question

Quote:
Originally Posted by S/V Alchemy View Post
Lastly, a DSC Mayday can be easier to relay to shore if you (for instance) are dismasted and just have a handheld with a DSC button.
While a station receiving your DSC distress call should respond to the vessel in distress via voice IF the DSC alert is never acknowledged and may also contact the coast guard via voice to inform them of the alert, DSC digital relaying is against the rules and class D units (recreational) are not even capable of relays. Commercial ships with class A were capable of manual digital relays but that has been against the rules for some time.

Eric
__________________
fairbank56 is offline   Reply With Quote
Old 24-06-2013, 18:44   #23
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Quote:
Originally Posted by fairbank56 View Post

The latest ITU DSC technical spec that I have doesn't give a number, it simply states "Once stored, it should not be possible for the user to change the MMSI number without advise from the manuafacturer."

Eric
Yes I think it may have changed

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 24-06-2013, 21:24   #24
Registered User

Join Date: Apr 2007
Posts: 718
Re: Another Dumb DSC VHF Question

I dug up earlier versions of the standard as far back as 1997 and none of them gave a specific number. The early versions state, "The MMSI should be stored in the DSC unit and it should not be possible for the user to easily change it." I think most manufacturers just allow you to screw up once. After that, it requires the programming software to change it.

Eric

__________________
fairbank56 is offline   Reply With Quote
Old 25-06-2013, 14:50   #25
Registered User

Join Date: Jun 2012
Location: Toronto ON
Boat: Morgan 33 O/I
Posts: 30
Images: 2
Re: Another Dumb DSC VHF Question

Thanks John, I can see I have a bit of exploring to do in the menus.

Quote:
Originally Posted by cal40john View Post
Only thing digital is channel 70.
Pushing the distress button sends your MMSI number and GPS location digitally. When the coast guard acknowledges your signal the radio automatically is switched to channel 16, where you talk which them just as you used to on an analog open to everyone channel.

You can place a call to another boat using their MMSI digitally. Only the boat being called announces your desire to talk. Their radio will change to the analog working channel that you have selected when they acknowledge. You then talk on a normal analog open to everyone channel.

There are other functions such as ask for your buddies GPS location which is sent to your radio and displayed.

John

Can You Hear Me?
__________________
AD 2 is offline   Reply With Quote
Old 25-06-2013, 21:37   #26
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Quote:
Originally Posted by fairbank56 View Post
I dug up earlier versions of the standard as far back as 1997 and none of them gave a specific number. The early versions state, "The MMSI should be stored in the DSC unit and it should not be possible for the user to easily change it." I think most manufacturers just allow you to screw up once. After that, it requires the programming software to change it.

Eric
Some radios allow upto to three

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 26-06-2013, 09:18   #27
Registered User
 
S/V Alchemy's Avatar

Join Date: May 2008
Location: Toronto
Boat: Custom 41' Steel Pilothouse Cutter
Posts: 4,577
Re: Another Dumb DSC VHF Question

Quote:
Originally Posted by AD 2 View Post
Yes we are at Mimico, only a friendship gate away from EYC. I just picked up the radio to replace an earlier non DSC model that was in the boat when we got it last year. I'm especially enamoured of the e-distress feature, and am looking forward to checking out the quality of the digital voicestream. I'm just waiting for the Ministry to send out the MMSI. And down the road, AIS is definitely on the radar. As they say.

I was checking out your blog – very nicely written. Alchemy’s a sweet looking boat. It looks like we have similar outlooks on life in general, particularly in the reduce/reuse/recycle department, and in not underestimating the value of the lo/no technologies of our forebears in the rush to embrace the shimmering gadgetry of the future. We put up substantial quantities of food in season, munching it leisurely for the rest of the year, and I very much enjoy the fermentation method of barley preservation, infusing an antibacterial agent (say, hops) and bottling the result under slight CO2 pressure. A skill’s no less of a skill for being ancient. As Isaac Newton may have said had it occurred to him, if we have trains, planes and automobiles (also boats), it is because we are driving over the heads of people who traversed continents on their feet.

We took our first baby boat steps this weekend, a stately procession of 12nm all the way to Oakville, and the radio was fine. Also our first baby radio steps, come to think of it. You are way further along your sailing trajectory than we are - who isn't? - so I very much appreciate the clarity of your kind and sagely advice.


Billy
Thanks for the kind words, Billy. The Morgan OI 33 is a sweet ride, if not a champ to weather (like mine, but unlike my equally old Viking 33). You should throw it into a nice brief Lake Ontario squall to get in practice time for the proper ocean. Lake Ontario, it is said and I concur, can give you plenty of practice dealing with short, heavy chop and intense squalls, and if you can handle that here without breaking crew or gear, you are well on the way for salt water. Just reef her well down, tether in, dog down the hatches and go looking for trouble. The Morgan should prove a good teacher.
__________________
Can't sleep? Read www.alchemy2009.blogspot.com for fast relief. Can't read? Avoid www.volumesofsalt.blogspot.com, because it's just personal reviews of sea books.
S/V Alchemy is offline   Reply With Quote
Old 26-06-2013, 09:22   #28
Registered User
 
S/V Alchemy's Avatar

Join Date: May 2008
Location: Toronto
Boat: Custom 41' Steel Pilothouse Cutter
Posts: 4,577
Re: Another dumb DSC VHF question

Quote:
Originally Posted by fairbank56 View Post
While a station receiving your DSC distress call should respond to the vessel in distress via voice IF the DSC alert is never acknowledged and may also contact the coast guard via voice to inform them of the alert, DSC digital relaying is against the rules and class D units (recreational) are not even capable of relays. Commercial ships with class A were capable of manual digital relays but that has been against the rules for some time.

Eric
Thanks for the clarification. I was referring to a voice response in the situation where a boat with perhaps a five-watt handheld at deck level sends a DSC distress call seven or eight miles downrange from a boat closer to shore and CG monitoring. The CG may not, for a variety of reasons, be able to hear the handheld DSC or the voice, but the intervening vessel may be able to be the middleman by voice with both boat in distress and shore.
__________________

__________________
Can't sleep? Read www.alchemy2009.blogspot.com for fast relief. Can't read? Avoid www.volumesofsalt.blogspot.com, because it's just personal reviews of sea books.
S/V Alchemy is offline   Reply With Quote
Reply

Tags
dsc, vhf

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Probably a Dumb Question: Why Are Edel Cats So Inexpensive ? deckofficer Multihull Sailboats 34 10-01-2015 09:38
Resistance to DSC VHF SV Enough Health, Safety & Related Gear 154 31-12-2011 22:03
DSC Watch Receiver on 2187.5 Securité Over a Long Distance funk-an-bord.de Marine Electronics 1 08-12-2011 08:27
Emergency VHF Antenna Question Chief Engineer Marine Electronics 39 22-10-2011 11:49
Dumb Question . . . SmartMove Families, Kids and Pets Afloat 3 11-09-2011 15:28



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 20:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.