Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-05-2015, 09:57   #16
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,532
Re: New HF-DSC Explanation and LIVE Demonstration Videos

With the recent discussions of Digital Selective Calling and specifically HF-DSC / SSB , I thought bumping this back up top might give some of you the chance to see it....

Watch the video playlists, and I think you'll enjoy!

HF-DSC Communications
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX



And, some others as well...

Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY


Maritime HF Communications
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y


Icom M-802 instruction Videos
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr



Fair winds to all..

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 28-06-2016, 12:39   #17
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,532
Re: New HF-DSC Explanation and LIVE Demonstration Videos

With all the talk of EPIRB's, "ditch bags", etc...and with the recent loss of a father and his 3 teenagers just off the coast of SW Florida, I thought some might want to know more about EPIRB's, how they work, how the COSPAS-SARSAT system works, etc....
As well as, remember that MF/HF-DSC signaling is just as big of a part of the GMDSS as the 406mhz EPIRB is...

So, for those wishing the details of EPIRB operations, and how to best deploy/use an EPIRB, please have a look here..
http://www.cruisersforum.com/forums/...ds-146617.html


Fair winds..

John
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 29-07-2018, 13:22   #18
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,532
Re: New HF-DSC Explanation and LIVE Demonstration Videos

While there haven't been many changes to the GMDSS....there are a few....like Iridium's new offering from their "NEXT" satellites (Certus) awaiting GMDSS certification, and INMARSAT's Fleet Broadband waiting on the same.....
But, with the prices of those systems and airtime/data costs, it's unlikely any of my fellow budget-conscience cruisers will be ordering any of those anytime soon!!

And, of course just a reminder that the USCG no longer monitors any MF / 2Mhz channels, not 2182 on SSB, nor 2187.5 DSC....
But, of course, DO monitor the remaining 5 GMDSS DSC freqs 24/7, from multiple locations!

https://www.navcen.uscg.gov/?pageName=cgcommsCall



So, there are of course parts of the GMDSS that we all use daily, and many other parts that we equip our boats with....and while the GMDSS was designed to work without specially-trained personnel, it is good to know something about radios, radiowave propagation, MF/HF-DSC, etc....
So, that's why I made all the videos that I did...

This fall, it will be a few years since I recorded/uploaded these videos...

And, while neither the radio nor the basic approach to using it has changed, what has changed is the ~ 11yr solar cycle (which regulates the foibles of long-range radio communication)....

As you can see from this graph, when I recorded most of these videos in Oct 2013 (and again in early 2015), the sunspot cycle wasn't great (avg SSN of 55 to 60), it was much higher than today, in 2018...




So...
So, this month (July 2018) I did another video, updating and describing current HF radiowave propagation for the offshore mariner (whether they use maritime or ham bands)...

This new video, together with my earlier video regarding channel / frequency choice and the basics of Radiowave Propagation, should give many of you some assistance in getting the most out of your HF communications system on-board.





I also added it to these playlists:

HF-DSC Communications
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX


Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY


Maritime HF Communications
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr



Fair winds to all.

John


P.S. FYI, here is my original video regarding channel / frequency choice and the basics of Radiowave Propagation, from Oct 2013...

__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 03-09-2018, 13:59   #19
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,532
Re: New HF-DSC Explanation and LIVE Demonstration Videos

Hello to all,
I just recently uploaded a couple new videos, showing LIVE, real-world Ship-to-Ship HF-DSC calls...

I've added them to my HF-DSC Playlist...please have a look....(and, please watch the playlist in order, so that it all will make sense)

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX


And, for those completely familiar with their radio and with HF-DSC, here are the videos:

"Live, Ship-to-Ship HF-DSC Calling, on GMDSS HF-DSC Calling Freqs"
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Old 28-07-2020, 11:30   #20
Registered User
 
ka4wja's Avatar

Join Date: May 2007
Location: Florida
Boat: Catalina 470
Posts: 2,532
Re: New HF-DSC Explanation and LIVE Demonstration Videos

Hello to all,

Once again I'd like to add some clarifying information.



Due to my efforts to promote HF-DSC, I unfortunately went too far and inadvertently caused some confusion....please ignore and forget my comments specifically dealing with "routine" HF-DSC signaling (you can skip that video, as well), unless you have some unique/specific need to investigate / learn about "routine" signaling....

Please just stick with the "Distress" (MayDay) signaling and "Safety" (Securite`) signaling (for weather, navigation, communications testing).



Those of us on private yachts, with the Icom M-802, etc., will mostly be using MF/HF-DSC for "Distress" signaling (MayDay) or "Safety" signaling (for weather, navigation / communications testing, etc.)....and that's probably it...


And, you're going to be using one of the six Int'l GMDSS DSC "Safety" / "Calling" frequencies
[2187.5khz; 4207.5khz; 6312.0khz; 8414.5khz; 12577.0khz; 16804.5khz]



Although, I already mentioned that the USCG offers "automated DSC Testing" on 4207.5khz, from 3 of their locations, if you are beyond 4mhz comms range, they do accept DSC "Safety" calls for testing / verifying proper HF-DSC system operation, as long as you don't do this often (typically once per year / once per season, or only prior to an ocean passage).



Some additional supporting info for this:
From US FCC Part 80 Rules & Regs (Maritime Mobile Service):

80.359 Frequencies for digital selective calling (DSC).

(b) Distress and safety calling. The frequencies 2187.5 kHz, 4207.5 kHz, 6312.0 kHz, 8414.5 kHz, 12577.0 kHz, 16804.5 kHz and 156.525 MHz may be used for DSC by coast and ship stations on a simplex basis for distress and safety purposes, and may also be used for routine ship-to-ship communications provided that priority is accorded to distress and safety communications. The provisions and procedures for distress and safety calling are contained in ITU-R M.541-9 (incorporated by reference, see 80.7), and 80.103(c).



And, some further info (primarily dealing with the equipment and crew familiarity):

Quote from US Gov't Pub 117:


Use of GMDSS Equipment for Routine Telecommunications; GMDSS telecommunications equipment should not be reserved for emergency use only.

The IMO has issued COMSAR/Circ.17 (dated 9 March 1998) which recommends and encourages mariners to use that equipment for routine as well as safety telecommunications. The following recommendation is extracted from Circ.17:

Use of GMDSS equipment for transmission of general radiocommunications is one of the functional requirements specified in SOLAS chapter IV, regulation 4.

Regular use of GMDSS equipment helps to develop operator competency and ensure equipment availability. If ships use other radio communication systems for the bulk of their business communications, they should adopt a regular program of sending selected traffic or test messages via GMDSS equipment to ensure operator competency and equipment availability and to help reduce the incidence of false alerts.


This policy extends to all GMDSS equipment suites including Digital Selective Calling (DSC) on VHF, MF and HF, to the Inmarsat systems, and to any duplicated VHF and long-range communications facilities.



{Over the years, I've attempted to be a bit less USA-centric, trying to point to the international uses of the GMDSS.....and I've mentioned some sailors recommendations for using MF/HF-DSC in ocean rallies, etc., as well as encouraging the use of "regional MMSI's" for regional-group calling... but these are rather specialized / niche uses, and I now realize that those interested in them will either already be aware or will be smart enough to ask/learn....so, no need for me to be rambling on about them... }



Without going into the weeds of the original GMDSS plan, nor specifically Digital Selective Calling (DSC), please remember that this system was originally designed/planned in the late 1980's / early 1990's, and implemented starting in 1992....so, much has changed....not the least of which most "public correspondence" (ship-to-shore phone calls) is handled via sat comm, as are most "data comms" that aren't being handled privately via PACTOR....


While the MF/HF-DSC system (as well as the VHF-DSC system) is an integral part of the GMDSS (Global Maritime Distress and Safety System), the main use these days is the "Distress" signaling and "Safety" signaling, not the "Routine" signaling that was intended to be used for both ship-to-shore and shore-to-ship signaling, by both "public coast stations" (for "public correspondence" and ship's/fleet's business) and "private coast stations" (usually for ship's/fleet's business, using SITOR/FSK)...


So, while we can continue to rely on the GMDSS to be there when we need it [406mhz EPIRB's; NAVTEX; VHF-DSC-FM; MF/HF-DSC-SSB; SafetyNET broadcasts; INMARSAT-C (and now / soon-to-be INMARSAT FB and Iridium Certus); SART's (AIS-SART's or SART-X's)], we should remember (or rather I should accept?) that most sailors/cruisers (except those using NAVTEX...mostly in Europe or Asia), these days only use the GMDSS in times of "Distress"....so...


So, perhaps we could learn something from the IMO (International Maritime Organization) that started the whole SOLAS (Safety-Of-Life-At-Sea) idea, and came up with the GMDSS in the first place?



Maybe we should heed their advice?


Have a look again at what their advice / recommendations are:
Use of GMDSS equipment for transmission of general radiocommunications is one of the functional requirements specified in SOLAS chapter IV, regulation 4.


Regular use of GMDSS equipment helps to develop operator competency and ensure equipment availability. If ships use other radio communication systems for the bulk of their business communications, they should adopt a regular program of sending selected traffic or test messages via GMDSS equipment to ensure operator competency and equipment availability and to help reduce the incidence of false alerts.


This policy extends to all GMDSS equipment suites including Digital Selective Calling (DSC) on VHF, MF and HF, to the Inmarsat systems, and to any duplicated VHF and long-range communications facilities.



Perhaps this is simply what I should have recommended from the beginning, some ~ 17 years ago, when I first started touting "HF-DSC"? But, whatever the case, that's what I recommending today!


I do hope this info is helpful to you all.

Fair winds.

John


P.S. Don't forget the "stickies" here, on Maritime HF Comms

Marine SSB Stuff (how-to better use / properly-install SSB, & troubleshoot RFI, etc.)
https://www.cruisersforum.com/forums/f13/marine-ssb-stuff-how-to-better-use-properly-install-ssb-and-troubleshoot-rfi-etc-133496.html


HF-SSB Radio, Proper Installation Tips/Techniques, etc.

https://www.cruisersforum.com/forums...tc-198305.html


And, for those looking for the easy-peasy link to a free video series / Playlists, have a look here:


HF-DSC Comms

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX


VHF-DSC Comms

https://www.youtube.com/playlist?list=PLnN6ygtZ3h2m-IejYg7J6QugtO2epizxF


Generic Maritime HF comms
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nPNdApNsZDo_Jk3NB_Bt1y


Offshore Weather
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2mPZAx2vWzdjTJjHlChruyY


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2npivDjoFrC-8QKVyMb4tVr


Offshore Sailing
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nbwAGh5DKgTCj15iyl6qoY
__________________
John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110
ka4wja is offline   Reply With Quote
Reply

Tags
dsc

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Icom M-802 Instr Videos(basic-adv) & LIVE DSC-Distress Call ka4wja Marine Electronics 51 03-09-2018 13:56
A most impressive demonstration of seamanship Craig Harlamoff Seamanship & Boat Handling 11 10-06-2006 23:45

Advertise Here


All times are GMT -7. The time now is 07:15.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.