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Old 03-07-2014, 13:31   #106
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Re: Ham Radio vs Marine SSB

"2182 is discontinued from US GOVERNMENT monotering. "

As I understand it, the US government is simply following the international policy set by the ITU, who make the global decisions on these matters. So you can expect 2182 to be unmonitored globally, unless any specific agency says otherwise.
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Old 03-07-2014, 16:00   #107
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Re: Ham Radio vs Marine SSB

The title of this discussion shows it was originally about "ham radios" vs. "marine radios", unfortunately this past spring the USCG had a website/IT problem and some of their restored pages had old/outdated/erroneous info on them....
So, the discussion turned to that topic, and the more important topic of so many erroneously thinking that "2182" was still the channel to tune to, to call for help!! (it hasn't been that way for 15 - 20 years, even though the USCG was still monitoring it until August 2013, it was NOT the channel to tune to, to call for help since the 1990's...see below for more details)


I had forgotten about this part of this discussion....
But, since others are still posting about this, perhaps it does need to be highlighted again???


1) First off, the USCG did correct the old/incorrect info on their website and thanked me for bringing it to their attention (it was just a IT issue, not a USCG ignorance issue!!)

But, understand that they have left some "generic" radio for boaters info on their general pages, since these pages are not completely specific to the USCG...

Have a look...

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

http://www.navcen.uscg.gov/pdf/marcomms/2MHzDistressWatchkeepingClosureSafetyAlert.pdf

http://www.navcen.uscg.gov/?pageName=mtBoater






2) As for "2182"....the USCG was one of the last to monitor this!!
MF/HF-DSC is what is monitored worldwide!! (and the USCG does still monitor some of the HF GMDSS Voice freqs...see the links posted above in #1)
Quote:
Originally Posted by hellosailor View Post
"2182 is discontinued from US GOVERNMENT monotering. "
As I understand it, the US government is simply following the international policy set by the ITU, who make the global decisions on these matters. So you can expect 2182 to be unmonitored globally, unless any specific agency says otherwise.
Actually Hellosailor, under the GMDSS, the IMO does still list 2182khz as a "Voice" Distress / Safety / Calling frequency....and in Sea Area A2, it can still be used as such...
And, it is still used by some vessels and coast stations, AFTER they have signaled one another via MF-DSC (on 2187.5khz), to pass traffic and/or coordinate assistance or rescue...(but, this is a fairly rare occurrence, outside of UK, EU, Med, etc..)

BUT, nobody (not ship, nor shore station) is required to monitor this frequency at all, and haven't been since January 1999 (> 15 years ago)...and even before that (since 1990 or even the late 80's), most "monitoring" of 2182khz by vessels at sea and many shore stations was NOT a "voice watch", but rather by using a "2182 watch receiver", which listened for the "two-tone alarm generator" which would be transmitted by SOLAS vessels in distress on 2182 (up until 1999)...

So, except for the minimal voice watch of the USCG on 2182 (and a few other shore stations), over the past 20 years, "2182" has NOT been monitored at all, and has NOT been the channel to tune to, to call for assistance!!

And, due to the high noise levels and poor antenna system efficiencies on the 2mhz/MF band, daytime VOICE (SSB) ranges typically are 100 miles or so, and nighttime ranges (limited by atmospheric noise) are typically only a few hundred (500 typ. max) miles...

BUT....


3) But, the above does NOT mean that 2182 is never used, nor that you should remove it from your radio...(not at all!!)

Under the GMDSS all MF/HF required monitoring is via DSC....both MF-DSC and HF-DSC....

In Sea Area A2, 2187.5khz DSC is the required monitoring freq/mode....and after a 2187.5khz DSC call is received, 2182khz SSB is then used to communicate any traffic / coordinate any assistance or rescue....

Effectively the US removed Sea Area A2, replacing in with Sea Area A3 right up to Sea Area A1....(Australia never established a Sea Area A2, and always covered their near offshore waters via HF comms, al a Sea Area A3)
Some may not be familiar with these terms...so, briefly:
A1 = within range of at least one VHF-DSC coast station (typically up to 20 miles offshore)
A2 = within range of at least one MF-DSC coast station (typically from 20 miles out to 100-150 miles offshore)
A3 = within range of at least one HF-DSC coast station and/or within coverage of INMARSAT satellites...
A4 = within range of HF-DSC coast stations, beyond coverage of INMARSAT satellites...


If you read some of the USCG reports and statements, they hadn't gotten any legitimate calls on MF for a long time (as opposed to many on HF), and the MF antenna systems (and transmitters/receivers) were literally falling apart and many required total replacement, or extensive maintenance / repair....
The decision was made to simply transfer all Sea Area A2 responsibility to the USCG HF stations providing Sea Area A3 coverage, which already have excellent coverage from 20 miles, out to more than 5000 miles...
(this move is what Australia did originally, as they never had a GMDSS MF system...)

As you can see, this was: a) a technology (DSC) decision; b) a mother nature (Radio noise) decision; and c) a money (replacing/rebuilding antennas, etc.) decision!!


But, it was NOT the USCG following any ITU, IMO, GMDSS mandate, as they did that > 15 years ago, and had been just continuing to monitor 2182khz for all these years for no real reason, and it was becoming impossible to continue to do so without spending a LOT of $$$$...




I hope this clears things up....


Fair winds..

John
s/v Annie Laurie
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Old 03-07-2014, 21:41   #108
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Re: Ham Radio vs Marine SSB

I believe that the Coast Guard of the USA has never officially declared a Sea Area A1. The most recent news I have seen on this issue dates from May 2104, which brought news of a continued delay by the USCG, apparently based on lack of coverage in Alaska.
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