SSB or SatPhone ?

[CarlF]

Allan,

I have no argument about the need for VHF. Both fixed and handheld. It is clearly the most important emergency signalling device and best way to coordinate rescue.

We see the role of HF differently. I have SSB, Ham, Satphone, EBIRB, PLB and now an InReach aboard. The HF equipment would be my backup to satellite in an emergency - not the other way around.

I agree that you may sail in a part of the world where HF is still justified. But in the North Atlantic and the Med, where I sail, it's fading away.

I believe marine use of HF is going to be a curiosity in ten years time. It will be interesting to see who is right

Carl

[goboatingnow]

Allan

Thank you for your response. The position of MRCC Australia and Hong Kong may be as you state.

It worries me that HF advocates see it neccessary to justify such radios by running down sat phones. The advocates of the reverse do not see it that way.

The fact is that HF installations have fallen on leisure yachts quite considerably over the previous 10 years. That is evidenced in many of the surveys that are collated amongst longer distance cruising yachts each year.

I would point out that, GMDSS carriage requirements can be accommodated by the carrying of MF and Inmarsat sat comms. There is no requirement to carry DSC HF. In my experience on board ships, I see far more reliance on sat comms then I do HF.

The fact is despite what you say, a sat phone makes a very useful rescue device, worldwide MRCC Falmouth has been used as a point of contact for many satphone ( and email ) initial distress calls, they then hand off such rescues to the relevant local MRCC.

Distress alerts by direct phone ( or email ) to an MRCC are just as effective as any other method of contacting an MRCC. These days with the preponderance of digital communications methods, it is becoming increasing popular to contact MRCC,s directly.

In my view, for simplicity of operation, and more importantly , the ability to bring a satphone into the liferaft, makes to an extremely useful communications tool, with several advantages over DSC HF. Couple this with EPIRB distress alerting and long distance cruisers have an extremely good rescuer communications system on board.

Not for a moment, would I suggest that makes DSC HF invalid. It's not an " either or " situation. If you have the resources fit both and learn and license the HF equipment appropriately.

But the fact remains. A satphone coupled with an Epirb, makes a more then adequate distress altering system, and the utility of a sat phone for normal communications aside from dstress alerting cannot be beaten. Talking to experts ashore, family , friends , the bank, the tax man etc, sat phones provide near mobile phone ease of use.

Dave


Sent from my iPad using Tapatalk

[carstenb]

Originally Posted by goboatingnow

only in a small part , most is a2

dave

Lisbon south to Cabe San Vicente - a fairish long stretch

[AllanR]

Dear Dave and Carl,


We seem to have exhausted all others, as no further comments have been received.


Perhaps I can try to clarify for other readers that – sitting in this much bigger, emptier side of the sailing, cruising, racing & rally world – I see your comments as relevant and appropriate in the context of cruising in Europe, North America and perhaps the North Atlantic that links them, because:


1. MRCC Falmouth does not have a HF/SSB radio, therefore they can only require that private and commercial vessels use a VHF radio (up to 30nm offshore), MF radio (30 to 150nm offshore) or satphone to contact them. All their systems are based upon these three communication options; no-cost marine VHF and MF calls for coastal communications and expensive satphone calls beyond that. The UK's S&R responsibility area is quite small, so VHF and MF will mostly do the job. If you want to talk to MRCC Falmouth when beyond their VHF/MF service range, be sure to have plenty of credit on the satphone account.


2. There is a lot of commercial and recreational vessel activity around the UK, in Europe, North America and across the North Atlantic routes which link them. These are also the regions of the world with the highest levels of income, taxation and spending. Most governments and not-for-profits have sufficient money to provide high standard 24/7 professional search and rescue capability with an effective service range beyond their coastal VHF/MF coverage. A satphone call to a central S&R authority with all those resources at their immediate disposal is very likely to result in a successful outcome.


But in contrast, on this bigger, emptier, lower wealth side of the world, the money to fund these excellent resources and capabilities simply does not exist in most areas. And especially not in the less congested, cheaper living, low income and environmentally intact regions most cruisers from Europe, the UK and North America wish to visit.

So while a VHF marine radio, satphone and EPIRB could be sufficient in the UK/Europe and coastal North American context – where relatively short distances, ample professional S&R resources and lots of commercial shipping is available to quickly direct to assist a yacht in distress – MRCC Australia makes the effort to advise that a satphone it is not sufficient or appropriate on this side of the world:


“In the event of an emergency, communication should first be attempted with others close by using radios, phones and any other signalling device.” (Because an unknown but nearby vessel is likely to be the quickest source of assistance. Therefore, a DSC alarm and voice call, broadcast by radio, is the most effective option; it can contact unknown vessels nearby.”)


“... not all of Australia's Search and Rescue Region can be reached by Australian based aircraft or by ships in a timely fashion.” (Because the area is big and resources are thinly spread.)


“The International Maritime Organization (IMO) has strongly recommended that non-SOLAS (Safety of Life at Sea - SOLAS) vessels (under 300 tonnes) to be fitted with GMDSS-compatible equipment.” (So they can connect to the established GMDSS marine radio network that already links commercial vessels. A satphone is not GMDSS-compatible. Marine VHF and HF/SSB radios with DSC are GMDSS compatible.)


“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.” (Because the unique broadcast feature of radio can alert known and unknown nearby vessels, the EPIRB can only alert the MRCC. Appropriate means marine VHF with DSC when in range of coastal VHF stations/towers and HF/SSB with DSC when beyond.)

“Depending on the circumstances, your initial distress alert should still be made by radio if possible. (Because it can alert a nearby vessel as well as the MRCC.) 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.” (Because minimal S&R resources and relatively light commercial shipping traffic means it could takes some days for an official response vessel to reach you. The EPIRB battery could go flat in that time.)

“Even once a (EPIRB) position is obtained, response times then depend on the time for a search and rescue (SAR) unit …. to be readied and transit to the search area. The more remote the location of the distress incident, the longer the response time. In all instances, be prepared to survive.” (Because distances are great, very few dedicated S&R resources exist, and commercial shipping densities are low.)

When GMDSS was introduced for commercial shipping, the UK focussed on VHF and MF, because that provided an effective technical answer that covered the very busy – recreational and commercial – traffic areas in their relatively small S&R region. In contrast, Australia dismantled it's existing linked VHF network (covering only parts of the east coast) and focussed on HF/SSB, because it was impractical to provide a VHF and MF service around the – mostly uninhabited – coastline, and HF/SSB also covered the enormous open ocean S&R responsibility area. Similarly, the USA – also responsible for a large open ocean S&R region in the north-western Atlantic and north-eastern Pacific oceans - declared it had no VHF or MF service, and focussed on HF/SSB. (Although a continuous coastal VHF network is now being established.) These differences are also reflected in the fact that Yachting Australia now requires all Category 1 and 2 events – and any event without continuous VHF coverage over and beyond the race area – to use HF/SSB radio. The circumstances in the UK/Europe are different to this side of the world, so the appropriate solution is different too.

The reason I am contributing to the forum is to highlight to cruisers from the UK/Europe and North America, that what they have come to expect from S&R services – including appropriate communication facilities – in their home country coastal cruising, racing & rally regions, cannot be expected on this side of the world; from the Panama Canal, across the Pacific, around most of Australia, in SE Asia, the Indian Ocean and South Atlantic. The modern DSC capable marine HF/SSB radio is designed to fill this vacuum by linking together mariners – recreational, commercial, government and tourism - so they can directly support each other, despite limited MRCC capabilities and despite being beyond direct marine VHF (with DSC) range.

I'm not sure of the source of statistics on HF/SSB radio installations, but:


1. If the respondents are principally from the UK/Europe, it is very understandable these yacht owners have stopped buying marine HF/SSB radios; the coastal VHF/MF systems are excellent and sufficient for most coastal cruising, racing and rallies. The immediate response, professional S&R resources mean that it is not necessary to rely on other mariners. And, around the UK there is presently no point having a modern DSC capable marine HF/SSB radio to make no-cost-calls to MRCC Falmouth; they do not have a similar radio. Expensive satphone calls are the only option when beyond MRCC Falmouth's no-cost-calls via VHF and MF service range.


2. It is also understandable that since the arrival of GMDSS for big ships, yachts operating beyond the high traffic density areas of UK/Europe and North America could choose to lose faith in the traditional use of HF/SSB radios for contacting commercial shipping. A voice call is very unlikely to get a response from most nearby ships and MRCCs, because they have taken the opportunity to follow the GMDSS regulations, muted their radio speakers and are only monitoring for DSC calls. To get back into the system, recreational vessels need to also utilise a DSC capable marine HF/SSB radio. It returns to recreational vessel crews the ability to contact other nearby mariners – commercial, tourism, government and recreational.


The individual and group calling features of DSC capable HF/SSB radios significantly increases the mutual assistance potential for recreational vessels in races, rallies or self-help groups to support each other, by maintaining a 24/7 DSC watch for calls for cost-saving and convenient advice, assistance, spare parts or a tow which could help prevent a rescue situation.


In North America, the Coast Guard has a very effective HF/SSB radio (with DSC) service, which fills any gaps in coastal VHF coverage, and extends free-to-talk emergency communications well offshore, into the North Atlantic and North Pacific.


Yachts that take advantage of the Coast Guard's no-call-cost HF/SSB service, weather broadcasts etc, and the mutual support advantages of 24/7 DSC monitoring, can also utilise the low-cost email service from the not-for-profit SailMail Association's over 20 linked stations around North America, in Europe, and the rest of the world, to download free GRIB charts, METAREA forecasts etc, and lodge free position reports. The email service savings via SailMail - compared to email via satphone - will pay for the HF/SSB radio equipment.


As a Churchill Fellow I learnt some years ago – when examining the operational, safety, equipment and staff training characteristics of adventure training/education organisations in the UK/Europe and North America – that simply applying the practices from one place into another is not a recipe for success. There are differences in resources, circumstances and capabilities. What we developed for Outward Bound operations in Australia would not work in the UK/Europe and North America; and we did not presume to think that it could.


I do not see MRCC Australia or RHKYC or Yachting Australia or MRCC Hong Kong saying their advice and procedures should necessarily apply in the UK/Europe or North American. But it does apply to this side of the world, because the S&R circumstances are very different.


My hope is that by highlighting these differences – along with the consistent advice from professionals in S&R and recreational boating on this side of the world – people planning to circumnavigate and to enjoy exploring these regions can equip themselves with the appropriate communication equipment to facilitate a more convenient, relaxed, mutually supportive, lower-cost and rewarding journey. And in the unlikely event that they need urgent assistance, they can get it quickly; as per the advice of the professionals on this side of the world who are dealing daily with such situations.


Yes, there are techniques to learn to take best advantage of HF/SSB communications, but the benefits are significant and not replicated by satphone. It's worth remembering that when Kay Cottee sailed single handed around the world in 1988, she maintained daily HF/SSB voice skeds with Derek and Jenine at Penta Comstat (north of Sydney, Australia) for the entire trip. Modern, DSC capable marine HF/SSB radios are far more effective, relatively lower cost, versatile, robust and compact. They are not as complex or problematic as a satphone salesman might claim.


With regard to Carl's suggestion that over the next ten years we'll see the need for HF/SSB radios disappear around Europe because satphones will replace them, I welcome the idea, because for that to occur it will mean that in addition to the existing very useful capabilities of satphones, conversations between yachts will be free, race and rally organisers can use them to make free broadcast calls to a fleet of boats, MRCCs can use them – for free – to simultaneously broadcast updates to all vessels in the area about a S&R situation, yachts will be able to call the Coast Guard and other MRCCs for no charge, and satphones will no longer stop working because the account has run out of credit.

But I suspect we should not hold our breath – or delay buying the DSC capable marine HF/SSB radio – while waiting for this to happen.

[suzanneconnely]

I've used single side band, Iridium sat phones, and of course have an EPIRB.

What I have found most useful is to augment my 2-way radio & SSB with the [relatively] new DeLorme inReach SE 2-way satellite communicator. You have to pay a subscription, about $25/month, but it's well worth it.

The sales rep at West Marine went over the device in detail with me and told me what I can, and cannot do with the inReach.

First, InReach SE uses the Iridium satellite network, so my family and I are always covered on trans-oceanic routes.

Second, you cannot make a call on the inReach, but you can pair it with your iPad or tablet and the inReach acts like a hotspot for global, 2-way texting. [Much cheaper than satellite telephone calls in the long run].

DeLorme allows App users to download NOAA nautical charts, so the inReach can also act as a GPS with built in mapping, for vessel monitoring/tracking.

I also confirmed that the SOS is monitored by GEOS in Texas, who has staged thousands of SOS's on like devices.

West Marine had a $50 rebate on inReach SE, and the device ended up costing me about $250. Plans are pay as you go. Service is worth its weight in gold.


Hope this helps,
Suzanne

[AllanR]

Originally Posted by suzanneconnely

I've used single side band, Iridium sat phones, and of course have an EPIRB.

What I have found most useful is to augment my 2-way radio & SSB with the [relatively] new DeLorme inReach SE 2-way satellite communicator. You have to pay a subscription, about $25/month, but it's well worth it.

The sales rep at West Marine went over the device in detail with me and told me what I can, and cannot do with the inReach.

First, InReach SE uses the Iridium satellite network, so my family and I are always covered on trans-oceanic routes.

Second, you cannot make a call on the inReach, but you can pair it with your iPad or tablet and the inReach acts like a hotspot for global, 2-way texting. [Much cheaper than satellite telephone calls in the long run].

DeLorme allows App users to download NOAA nautical charts, so the inReach can also act as a GPS with built in mapping, for vessel monitoring/tracking.

I also confirmed that the SOS is monitored by GEOS in Texas, who has staged thousands of SOS's on like devices.

West Marine had a $50 rebate on inReach SE, and the device ended up costing me about $250. Plans are pay as you go. Service is worth its weight in gold.


Hope this helps,
Suzanne

Hi Suzanne,

This looks to be a very useful satellite based backup option at a reasonable price. I assume since it is Iridium based, it is available around the world?

I will certainly look into this as a backup option for my own offshore activities. And recommend it to people who I'm also advising to install a HF/SSB radio; very convenient and reasonably priced for regular offshore boaties - fishermen, yachties, surf/dive charter boats etc - to have direct contact with family, the office, key clients, etc ashore, at a reasonable price.

Many thanks for this info. It appears to be smart technology, smartly applied.

Best wishes

Allan

[RobbieW]

Interesting reading in this thread for any of us considering voyaging into the Pacific.

One curiosity question that came up whilst reading; I have an ICOM710 installed, I also have licences for both marine and Ham bands. It ought to be possible, perhaps not even difficult with the right skills, to build a PC application to synthesise DSC calling and control the set - much as Airmail does for emails. That would provide a low cost upgrade route to DSC.

Is such a thing feasible ? Has anyone done it ?

[AllanR]

Originally Posted by RobbieW

Interesting reading in this thread for any of us considering voyaging into the Pacific.

One curiosity question that came up whilst reading; I have an ICOM710 installed, I also have licences for both marine and Ham bands. It ought to be possible, perhaps not even difficult with the right skills, to build a PC application to synthesise DSC calling and control the set - much as Airmail does for emails. That would provide a low cost upgrade route to DSC.

Is such a thing feasible ? Has anyone done it ?

Hi Robbie,

A very interesting suggestion. I do not know of such an option in a PC, but perhaps someone in the HAM world has more information.

I recall when I first started using HF/SSB radio in land operations in Australia there was an optional mic available that generated what was then known as the SelCall signal to call radios with a muted speaker but scanning for SelCall alerts. This allowed people with radios - that were not originally fitted with SelCall internally - to generate and send a SelCall ID and thereby catch and wake-up a scanning SelCall muted radio. Something similar might be possible/available to mimic DSC calling. But I do not recall that it allowed the radio to have a SelCall identity, and scan with a muted speaker for SelCall alerts.

Jenal brand if I recall correctly. An internet search might yield results. But I do not know if SelCall is compatible with marine service DSC.

Regards

Allan

[ka4wja]

Robbie,
I applaud your initiative (and while your idea is technically possible, it isn't very practical)...
The solution to your problem (not having an MF/HF-DSC-SSB Radio) is to buy/install an MF/HF-DSC-SSB Radio, such as the Icom M-802...
All new Marine HF transceivers sold in the US for the past 9 - 10 years, have been DSC-equipped (as required by law)....
So, while the M-710 is a fine rig, if you do desire to equip yourself with MF/HF-DSC capabilities, the only real solution is to buy a new radio...

Originally Posted by RobbieW

I have an ICOM710 installed, I also have licences for both marine and Ham bands. It ought to be possible, perhaps not even difficult with the right skills, to build a PC application to synthesise DSC calling and control the set - much as Airmail does for emails. That would provide a low cost upgrade route to DSC.

Is such a thing feasible ? Has anyone done it ?

The answer to your questions...
a) Is it possible? Yes, technically....but not very practical....

b) Is it feasible? NO....Not feasible...

c) Has anyone done it? I know of nobody that has set-up a computer on-board and used it to send/rec DSC messages....
Of course, some HAVE certainly used their PC's to copy (receive) HF-DSC signals, this is pretty easy....(HF-DSC is a 10-bit, 100-baud SITOR-FEC signal, so copying the signal is rather plug 'n play...)
Most who have done so, have done this from shore / at home, not on-board...

And, I assume that some have the software/modems that would allow transmission of the signals.....but you will need to read thru the ITU regs, to get a handle on message protocols / formats, etc....before you even begin to write PC software to send a DSC message...(see below for details)

And, most importantly here...
Understand that the HF-DSC system is duplex....in that it is designed with separate DSC receivers (built-in to DSC transceivers, or separate/dedicated DSC scanning receivers connected to MF/HF-DSC-SSB transceivers) that allow DSC reception even while the main unit is transmitting (whether it be voice, text, or DSC), and one of the DSC specs/rules states that the units MUST be able to receive their DSC ACK message even while transmitting a DSC Distress Call...
So, trying to do this with one radio, isn't actually possible...
(and when you factor in what a separate scanning receiver would cost....you're going to spend less money if you just bought an Icom M-802...)


d) Back to the "feasibility"....
I'm assuming your main goal for HF-DSC-signaling is for DSC-Distress calling???
If that's the case, then I don't see your idea in anyway feasible!!
You'd need to leave a PC running 24/7, connected to its own GPS receiver at all times, with your new DSC software up and running 24/7 as well, just to be able to have it available when you needed it....and have this PC connected permanently to the radio....
(and, you'd need to be sure that your software and PC were both "bug-free" and 100% reliable...)
And, you'd have to have the electrical power to run a PC, software, etc. 24/7, while out on passage...(now a very small minority of boats do this, though it is beyond me why...it isn't done by most...)

So, to be 100% honest here, it just doesn't seem to be in anyway feasible!!!

I do hope this helps...


FYI, there are 59 pages of specs/rules on Maritime DSC, form the ITU that you'd need to follow precisely, in order to even begin to get your idea to work...
Here is just one page....

1 General
1.1 The system is a synchronous system using characters composed from a ten-bit errordetecting
code as listed in Table 1.

1.1.1 The first seven bits of the ten-bit code of Table 1 are information bits. Bits 8, 9 and
10 indicate, in the form of a binary number, the number of B elements that occur in the seven
information bits, a Y element being a binary number 1 and a B element a binary number 0. For
example, a BYY sequence for bits 8, 9 and 10 indicates 3 (0 × 4 + 1 × 2 + 1 × 1) B elements in the
associated seven information bit sequence; and a YYB sequence indicates 6 (1 × 4 + 1 × 2 + 0 × 1)
B elements in the associated seven information bit sequence. The order of transmission for the
information bits is least significant bit first but for the check bits it is most significant bit first.

1.2 Time diversity is provided in the call sequence as follows:

1.2.1 Apart from the phasing characters, each character is transmitted twice in a time-spread
mode; the first transmission (DX) of a specific character is followed by the transmission of four
other characters before the re-transmission (RX) of that specific character takes place, allowing for
a time-diversity reception interval of:

1.2.1.1 400 ms for HF and MF channels, and

1.2.1.2 331/3 ms for VHF radio-telephone channels.

Rec. ITU-R M.493-13 3
1.3 The classes of emission, frequency shifts and modulation rates are as follows:

1.3.1 F1B or J2B 170 Hz and modulation rate of 100 Bs (bit/s) ・} 30 × 106 for use on HF and MF
DSC calling channels. When frequency-shift keying is effected by applying audio signals to the
input of single-sideband transmitters (J2B), the centre of the audio-frequency spectrum offered to
the transmitter is 1 700 Hz. When a DSC call is transmitted on HF and MF working channels for
public correspondence, the class of emission is J2B. In this case, audio tones with frequencies
1 700 Hz ・} 85 Hz and modulation rate 100 Bs (bit/s) ・} 30 × 106 are used in order for the DSC call to
be transmitted.

1.3.2 Frequency modulation with a pre-emphasis of 6 dB/octave (phase modulation) with
frequency-shift of the modulating sub-carrier for use on VHF channels:
– frequency-shift between 1 300 and 2 100 Hz; the sub-carrier being at 1 700 Hz;
– the frequency tolerance of the 1 300 and 2 100 Hz tones is ・} 10 Hz;
– the modulation rate is 1 200 B s (bit/s) ・} 30 × 106;
– the index of modulation is 2.0 ・} 10%.

1.3.3 The radio-frequency tolerances of new designs of both transmitters and receivers in the MF
and HF bands should be:
– coast station: ・} 10 Hz,
– ship station: ・} 10 Hz,
– receiver bandwidth: should not exceed 300 Hz.

1.4 The higher frequency corresponds to the B-state and the lower frequency corresponds to the
Y-state of the signal elements.

1.5 The information in the call is presented as a sequence of seven-bit combinations
constituting a primary code.

1.5.1 The seven information bits of the primary code express a symbol number from 00 to 127, as
shown in Table 1, and where:

1.5.1.1 the symbols from 00 to 99 are used to code two decimal figures according to Table 2;

1.5.1.2 the symbols from 100 to 127 are used to code service commands (see Table 3).

1.6 Where the distress alert repetitions described in § 11 apply, the following conditions are
considered necessary:

1.6.1 the transmitter encoder must provide repetitive transmission of the call sequence in
accordance with § 11; and

1.6.2 the receiver decoder should provide maximum utilization of the received signal, including
use of the error-check character and by using an iterative decoding process with adequate memory
provision.

1.7 When the transmission of a DSC distress alert is automatically repeated, ships’ DSC
equipments must be capable of automatically receiving a subsequent distress acknowledgement (see

Recommendation ITU-R M.541, Annex 1, § 3.1.3.1, 3.1.3.2 and 3.3.5).

And, here's just one more page...

Ten-bit error-detecting code

Symbol
No.
Emitted signal
and bit position
1 2 3 4 5 6 7 8 9 10
Symbol
No.
Emitted signal
and bit position
1 2 3 4 5 6 7 8 9 10
Symbol
No.
Emitted signal
and bit position
1 2 3 4 5 6 7 8 9 10

00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
BBBBBBBYYY
YBBBBBBYYB
BYBBBBBYYB
YYBBBBBYBY
BBYBBBBYYB
YBYBBBBYBY
BYYBBBBYBY
YYYBBBBYBB
BBBYBBBYYB
YBBYBBBYBY
BYBYBBBYBY
YYBYBBBYBB
BBYYBBBYBY
YBYYBBBYBB
BYYYBBBYBB
YYYYBBBBYY
BBBBYBBYYB
YBBBYBBYBY
BYBBYBBYBY
YYBBYBBYBB
BBYBYBBYBY
YBYBYBBYBB
BYYBYBBYBB
YYYBYBBBYY
BBBYYBBYBY
YBBYYBBYBB
BYBYYBBYBB
YYBYYBBBYY
BBYYYBBYBB
YBYYYBBBYY
BYYYYBBBYY
YYYYYBBBYB
BBBBBYBYYB
YBBBBYBYBY
BYBBBYBYBY
YYBBBYBYBB
BBYBBYBYBY
YBYBBYBYBB
BYYBBYBYBB
YYYBBYBBYY
BBBYBYBYBY
YBBYBYBYBB
BYBYBYBYBB
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
YYBYBYBBYY
BBYYBYBYBB
YBYYBYBBYY
BYYYBYBBYY
YYYYBYBBYB
BBBBYYBYBY
YBBBYYBYBB
BYBBYYBYBB
YYBBYYBBYY
BBYBYYBYBB
YBYBYYBBYY
BYYBYYBBYY
YYYBYYBBYB
BBBYYYBYBB
YBBYYYBBYY
BYBYYYBBYY
YYBYYYBBYB
BBYYYYBBYY
YBYYYYBBYB
BYYYYYBBYB
YYYYYYBBBY
BBBBBBYYYB
YBBBBBYYBY
BYBBBBYYBY
YYBBBBYYBB
BBYBBBYYBY
YBYBBBYYBB
BYYBBBYYBB
YYYBBBYBYY
BBBYBBYYBY
YBBYBBYYBB
BYBYBBYYBB
YYBYBBYBYY
BBYYBBYYBB
YBYYBBYBYY
BYYYBBYBYY
YYYYBBYBYB
BBBBYBYYBY
YBBBYBYYBB
BYBBYBYYBB
YYBBYBYBYY
BBYBYBYYBB
YBYBYBYBYY
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
BYYBYBYBYY
YYYBYBYBYB
BBBYYBYYBB
YBBYYBYBYY
BYBYYBYBYY
YYBYYBYBYB
BBYYYBYBYY
YBYYYBYBYB
BYYYYBYBYB
YYYYYBYBBY
BBBBBYYYBY
YBBBBYYYBB
BYBBBYYYBB
YYBBBYYBYY
BBYBBYYYBB
YBYBBYYBYY
BYYBBYYBYY
YYYBBYYBYB
BBBYBYYYBB
YBBYBYYBYY
BYBYBYYBYY
YYBYBYYBYB
BBYYBYYBYY
YBYYBYYBYB
BYYYBYYBYB
YYYYBYYBBY
BBBBYYYYBB
YBBBYYYBYY
BYBBYYYBYY
YYBBYYYBYB
BBYBYYYBYY
YBYBYYYBYB
BYYBYYYBYB
YYYBYYYBBY
BBBYYYYBYY
YBBYYYYBYB
BYBYYYYBYB
YYBYYYYBBY
BBYYYYYBYB
YBYYYYYBBY
BYYYYYYBBY

YYYYYYYBBB

EDIT:::
No, Selcall systems are not compatible and not adaptable to DSC...audio tome signaling / DTMF signaling and DSC, are miles apart...




Fair winds...

John
s/v Annie Laurie

[RobbieW]

Originally Posted by ka4wja

...Understand that the HF-DSC system is duplex...and one of the DSC specs/rules states that the units MUST be able to receive their DSC ACK message even while transmitting a DSC Distress Call...

Thanks John; that requirement, whilst understandable, is a bit of a bummer!

However, given the M710 had an add on for DSC

..It is an outboard 6-channel scanning DSC receiver, with xmit/rec DSC modem, and remote control unit for the M-710....

(from one of your posts in 2011) the extra hardware probably isnt too hard to achieve - but dont fret, I dont suppose I'll take the thought any further. It was as much 'if adding DSC could be done for an M710, why not for a ham transceiver (with appropriate frequency control)'

[ka4wja]

Robbie,
Cool that you found one of my old postings on this....
But, just an FYI....the reason I did not mention the old Icom 6 ch, scanning DSC rec (and its built-in sitor encoder/modem) is because nobody has seen one of these in 10 years or so....(and I'm not clear how many were ever manufactured...perhaps only a couple dozen), so finding one would not be an easy task...

Originally Posted by RobbieW

However, given the M710 had an add on for DSC (from one of your posts in 2011) the extra hardware probably isnt too hard to achieve - but dont fret, I dont suppose I'll take the thought any further. It was as much 'if adding DSC could be done for an M710, why not for a ham transceiver (with appropriate frequency control)'

If you do wish to look....I'd look at some of the "ship breakers" in asia....or some old fishing boat chandleries (perhaps in the PNW??)....just don't get your hopes up...


Bottom line:
If you desire MF/HF-DSC, the least expensive option is to buy/install an Icom M-802....
A new M-802, sells for about $1850....

Icom SSB Radio Kits & Components


(BTW, there was a used/like new M-802 that just sold on ebay last week, for about $1300....)


Fair winds...

John
s/v Annie Laurie

[macconews]

Has anyone used the iSavi for satellite commuications, developed for Inmarsat’s IsatHub service?

[GMN]

Hi,
This is Topher from Global Marine Networks. I would just like to point out two blogs that may add value to this discussion when comparing SBB to Satellite systems.

Talking about the Costs of Radio
HF Radio vs. Satellite Phones: What is Really "Free"?

Talking about the advantages and disadvantages of both
HF Radio and Pactor Modems vs. Satellite Phones for Email at Sea

[svjohngalt]

Also consider you can get a good SSB receiver for under $200.00 and download an android or PC weather fax receiving software. This gives you all the "receiving" options of any SSB. You can also listen in on the nets and weather nets. Given the cost to transmit, what is the purpose of the SSB as it relates to transmitting? I would think generally, making any arrangements at a marina you would want to use VHF. Lets face it, if in an emergency, if you can't raise anyone by VHF and have to go to SSB, nobody is coming any time soon. You are better off with a Sat phone and or a Spot type device.

The sat phone is cheap and now there are sat devices for texting which lower the cost even further. It seems the $3K to $4K to transmit on SSB my not be totally worth it. Last time I used a sat phone, incoming text were free. One could even have family just text updates on weather etc.

The electronics are evolving fast and the quality and reliability are improving almost daily. We are seeing fundamental changes in marine navigation and communications on the scale of when the compass was introduced or the clock itself. It is exciting to see this change and participate in it.

George

[Auspicious]

I think you are missing important points.

Originally Posted by svjohngalt

Also consider you can get a good SSB receiver for under $200.00 and download an android or PC weather fax receiving software. This gives you all the "receiving" options of any SSB. You can also listen in on the nets and weather nets.

All true. The price is even a bit lower than you say. The only sticking point is that newer laptops with combi-jacks need a cable to be made up since the availability of commercial products is limited.

Originally Posted by svjohngalt

Given the cost to transmit, what is the purpose of the SSB as it relates to transmitting? I would think generally, making any arrangements at a marina you would want to use VHF. Lets face it, if in an emergency, if you can't raise anyone by VHF and have to go to SSB, nobody is coming any time soon. You are better off with a Sat phone and or a Spot type device.

There are other scenarios.

There are many arrangements that may need to be made further in advance than VHF range permits. The ability to use email offshore means you can order parts and have them actually there when you arrive. You can find and arrange for services that are ready when you are instead of when they get to you. This capability is available with both HF/SSB and satellite devices.

As far as calling for help is concerned HF/SSB really shines. Push the red DSC button and alarms go off on every ship and well-equipped boat within hundreds of miles. The commercial ship 200 miles away will be with you in ten hours. Depending on how far offshore you are a sat phone call to SAR could be two or three times that long to first contact. Of course if you are coastal cruising response time is faster and you can always head into the two-bar line and use your cell phone, assuming you have a phone and a service that work with the local system. Your Verizon account is not so useful outside the US. Your satellite phone requires that you have a phone number for someone useful who will call SAR who will route to the cognizant RCC. Remember the telephone game we played as kids? Just how long will it take to get the right information to SAR and AMVER?

Incidentally, consumer satellite phones are still not part of GMDSS. Neither are SPOT or InReach.

Originally Posted by svjohngalt

The sat phone is cheap

How long are you going cruising? Break even for most people is about four years. That's just cost.

Originally Posted by svjohngalt

One could even have family just text updates on weather etc.

160 characters at a time? I don't think so. I'll take my synoptics over weather fax thank you, as you cited initially.

On deliveries I deal with a wide range of communications. I sell and service satellite communications systems. I still prefer HF/SSB over satellite. YMMV.