Originally Posted by btrayfors
With respect, seems like Allan has climbed aboard John's DSC bandwagon!
Yes, DSC is helpful and does all the stuff he writes about.
HOWEVER, his recent posts and John's many posts lead one to believe that the 710 and other non-DSC transceivers are "old technology" and somehow flawed because they don't have DSC capability. Nearly worthless, the ill-informed reader is to believe.
That's simply NOT TRUE. HF/SSB radios without DSC are still very useful and many, many cruising boats are happily using them every day.
Here in the U.S. the USCG monitors several HF emergency frequencies 24/7. The commercial
ship's telephone stations, WLO in Mobile AL and KLB near Seattle
several HF frequencies 24/7. They also provide weather broadcasts and ship call lists periodically during the day. You don't need a DSC radio to call the "marine operator" or make a telephone call thru these stations.
There are a number of marine SSB nets which operate daily, and which are very active. You don't need a DSC radio to tune into or participate in these.
Pactor modems work very well with the M710 and other HF rigs. You can send/receive emails from anyplace in the world (and you could even send a distress
message this way). Again, no DSC radio is needed.
Most marine transceivers are capable of transmitting on the amateur radio bands (the ham bands). There is activity over wide swaths of ocean almost 24 hours a day on 14300 kHz. Somebody somewhere will hear you, as hundreds of ham stations are listening at any given time. The Coast Guard often comes up on 14300 when they know there's an emergency -- when they do, their very powerful transmitters and antennas sound like the voice of god!
NO, Allan, no disrespect intended. But I've been deeply involved in marine communications for over 50 years and in numerous locations around the world, and I believe that the "imperative" of DSC has been overstated.
Mandatory? Certainly not.
I agree that the M710 certainly has a lot of very useful life in it for a lot of very important purposes, and as I mentioned in my earlier post, I own five.
But without Selective Calling, the M710 is seriously hampered as a radio to facilitate an always on communication network for small-craft, and to link small-craft crews into the well established and existing GMDSS/DSC network that helps protect big ship crews.
The M710 is already redundant in big ships, which must operate a GMDSS/DSC radio which can maintain a quiet 24/7 watch without the crew being tempted to turn down the volume or switch off the radio once they clear port and officials are not around to check. A SOLAS vessel with an M710 fitted instead of a GMDSS/DSC radio cannot get it's radio certificate and is not permitted to take it's crew or cargo to sea. The people who make decisions about these matters have seen the important life-saving benefits of DSC and acted upon this evidence, so it's convenient for all those big ship crews to maintain a 24/7 watch for calls from other nearby vessels. Yacht crews can tap into this always on, 24/7 watch, by big ships, just by fitting a DSC capable radio.
I also agree that HAMs have provided a great service
to yacht crews over many years and I hope that will continue while yachts still carry non DSC radios. However, to be very honest, my picture of ideal is dedicated and committed HAM net operators equipped with a DSC capable marine radio. That would be a powerful combination.
With regard to being mandatory, a DSC capable HF/SSB radio is mandatory for all Royal Hong Kong
Yacht Club events
beyond the range of coastal VHF
(with DSC) services. Without a functional DSC HF/SSB radio you cannot enter the race
. And Yachting Australia
- in its latest Special Regulations
, "for racing
and recommended for cruising" - requires all new and replacement HF/SSB radio installations to be DSC capable. We expect that in the following Special Regulations
period - to begin June 2017 - DSC HF/SSB radios will be mandatory for events
(with DSC) coastal services; like RHKYC. Maritime authorities in Australia
, the UK, Europe
and others will not license
a HF/SSB radio for small-craft use unless it is DSC capable.
In the UK, it has not been mandatory for yachts to have a HF/SSB radio when operating beyond their coastal VHF (with DSC) services. That's probably because MRCC Falmouth does not own a HF/SSB radio, and because the UK's S&R responsibility area is quite small, with VHF and MF sufficient for most area. MRCC Falmouth's only option when yacht owners ask about comms beyond their VHF service is to say get a satphone to phone
them. That's OK when yachts are still within range of their excellent RNLI lifeboats etc. But as the Chiki Rafiki demonstrated, it does not necessarily work elsewhere. If UK and Europe
registered yachts do fit a HF/SSB radio, it is mandatory to fit one with DSC.
While there are strong supporters of DSC for recreational marine HF/SSB radios - eg retired US Navy
Commander and committed cruiser, Terry Sparks - www.made-simplefor-cruisers.com
- what we see on this side of the world is a lot of USA cruisers in trouble because they do not have DSC capable radios and they cannot contact MRCCs or big ships when they need to.
I've written a longer document regarding why I support the use of DSC for marine HF/SSB and VHF comms and it can be seen here:
The short version is like this:
I have not recently climbed aboard John's DSC bandwagon, I've been on the Selective Calling bandwagon since the late 1970s, when I first bought HF/SSB radios for the adventure education centre I was working at in Australia. I was fortunate to have a HAM friend show me how HF radio could help us manage operations, reduce costs and increase safety
when conducting programmes in isolated areas. But the problem was the noisy radio, scanning through the 6 frequencies in the centre of the operations rooms, or in an isolated basecamp or 4WD. It would drive everyone crazy and sure to be the point that caused the entire concept
of radio communications to fail completely. It was inevitable the volume would be turned down or the radio turned off just for a few minutes during a briefing and never reset or tuned on again. It was the Achilles heel of a great technology. The availability of Selective Calling in commercial HF/SSB radios solved
the problem. These HF/SSB radios with SelCall provided excellent value communications for this not-for-profit organisation for more than twenty years of remote
Another magical feature of Selective Calling systems in HF/SSB, VHF and UHF CB radios is the revertive tone. When the called radio receives its SelCall ID, it opens it's speaker so the subsequent voice call can be heard and rings to attract atention. It also transmits a beep tone. This beep confirms to the caller that contact has been made with the desired radio. This eliminates many of the uncertainties with radio use Is the other radio turned on? Is it in range? Have I used the right frequency? Is my radio working properly? The revertive tone answers all these questions. The only remaining question is whether someone is nearby to hear the call and respond; or is away from the radio and/or busy.
In marine radio in Australia, SelCall was used to contact coast radio stations - and receive a confidence building revertive tone - since the late 1970s till the arrival of GMDSS in 1999. We all learnt that SelCall precipitated a far quicker and more dependable response than simply calling by voice. It was a lot easier for the operators too. Many Australian yachts and commercial small-craft had marine radios such as the Codan 9390, with SelCall. In a more advanced form it was used to connect with the automated telephone interconnect system available on certain frequencies, to directly dial the required shore or mobile phone
number from the yacht.
I admit to being a convert to Selective Calling (DSC or SelCall) for almost 40 years. I've learnt how it makes radios for more people friendly, helps it work for busy people (eg: operating a short-handed yacht, driving a vehicle and running a business), and it overcomes the human instinct to turn off the radio or turn down the noise
of the radio; especially the HF/SSB radio scanning through it's frequencies. In the Australian land and marine services, SelCall was a key factor in creating the system effectiveness and reliability
, for boat to boat, vehicle to vehicle or boat to vehicle calling, for contacting a coast station, and for emergency situations. Because people could leave the (silent) radio switched on and checking for incoming calls, 24/7. It really helped make HF/SSB radio a valuable communications resource that addressed regular people's day to day communication needs in isolated locations. And it still does.
Without DSC, hands up all the cruisers who put the safety and well-being of fellow cruisers above their own convenience, tranquility and sanity, by maintaining a 24/7 scanning watch on the open voice distress frequencies, with the volume turned up to ensure they can hear any calls from the cockpit
, when underway and while in a peaceful anchorage.
If the Chiki Rafiki incident is any measure, the answer must be none. Hands up again all the cruisers who if nearby to Chiki Rafiki would have maintained their open speaker HF/SSB radios with the speaker turned up loud enough to hear a voice call for assistance from Chiki Rafiki above the noise of waves, wind
, flapping sails
, yelling crew and slamming boat at that time. The DSC option really is far more practical.
Just over a hundred years ago, more than 1500 passengers on the Titanic learnt the hard way that switching off the radio is deadly. Radio operators on RMS Titanic and the nearby SS Californian within sight and stopped for the night amongst the icebergs had been communicating earlier that evening, but the SS Californian operator switched off the ship's radio ten minutes before the Titanic hit the iceberg and went to bed
. Perhaps they had planned to talk again in the morning, but it took the Titanic less than 2.5 hours to be gone, with over 1500 people left dying in the ice cold, calm seas. All done, dead and finished before the next radio sked. A significant safety related outcome of the Titanic enquiries was that radio equipment on passenger ships was manned around the clock (Wikipedia)
Yachts and other small-craft do not have the space or finance to assign a couple of crew to maintain a 24/7 listening watch on the HF/SSB voice distress frequencies. But technology has handed us their replacement, the electronics
in a DSC capable HF/SSB radio. These computer chips are happy to spend all day every day listening for calls, quietly, while we enjoy the contrasting challenge and tranquility of sailing and cruising. These radio chips don't need a bunk, food
, salary, vacations, days off or air flights. They just need access to the backstay and some electricity.
Many present day yacht crews are still not aware of their importance as a resource to help other mariners, and therefore the importance of keeping their radio switched on 24/7 at sea and at anchor to sustain a mutual support network; for advice, assistance and emergencies. Nearby yachts could have helped the Titanic passengers, and may have been able to help the Chiki Rafiki crew - either before the inversion or afterwards to intercept the PLB in the water
but were not contactable by either Chiki Rafiki (no HF/SSB radio?) or the US Coast Guard, or any HAM operators, because like the SS Californian their HF/SSB radios were apparently turned off.
Australia's MRCC has been stating the most effective answer for emergency assistance clearly and repeatedly on successive versions of their website for many years, because like many MRCCs, yacht clubs and yachting associations in this bigger, empty side of the world they recognised years ago what the MAIB report of the Chiki Rafiki incident has emphasized again, that expecting someone on a distant shore to sort out an emergency is not reliable, and not prompt. "While satellites and satellite-compatible distress beacons have significantly improved the effectiveness of SAR operations, the system is not a substitute for carrying appropriate marine or aviation radio ... Depending on the circumstances, your initial distress alert should still be made by radio if possible. You should activate your distress beacon only if contact cannot be made by any other means or when told to do so by a rescue
authority .... In the event of an emergency, communication should first be attempted with others close by using radios .... The basic concept
of the Global Maritime Distress and Safety System (GMDSS) is that search and rescue
authorities ashore, as well as shipping
in the immediate vicinity of a ship in distress, will be rapidly alerted to a distress incident so they can assist in a coordinated search and rescue operation with the minimum of delay." (AMSA website)
A marine HF/SSB radio has the broadcast style communications medium required to make direct contact with any other nearby vessels; without needing to know who is there or to know their satphone number. DSC in all radios ensures a much higher probability of nearby vessels having their radios switched on and maintaining a 24/7 watch for calls from anyone else. MRCC Australia knows this is a superior combination that works, because the maritime radio service in Australia has been using Selective Calling in HF/SSB radios since the 1970s. Its efficacy is well proven; over and over again.
Like the SelCall I have used for 40 years which is still widely used in the Land Mobile service in Australia Selective Calling for marine radios makes it workable for everyone to keep their radio on, so the mutual support and emergency assistance benefits of yacht crews helping other yacht crews can be achieved. When the radio is turned off - eg: between skeds - that yacht, it's equipment
and it's resourceful crew cannot know their help is needed by another nearby yacht crew with a problem, or any other nearby mariners; including passengers on the next Titanic. Whether the call for assistance is coming direct from the concerned crew on another vessel, or from an MRCC looking for nearby vessels to assist, the radio needs to be turned on. It really is that simple. History
proves it over and over. DSC makes it practical to do so.
I hope this is useful and informative for Ted and Relinda, and any other "newbies" contemplating their first HF/SSB radio. And especially for cruisers planning passages onto this side of the world, or into any regions where prompt response S&R services are not available.