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Old 09-01-2011, 18:28   #31
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Originally Posted by Seahunter

Homeland Security pulls the plug on all domestic satellites including GPS and private communication that are GPS dependent, it's SOP. Even if they don't turn off communication satellites, navigation satellites are down, and hand-held sat-phone cannot find the satellite because the GPS lock won't functioning.
As for size of the antenna; take a look at a freighter sometime and you'll notice those big domes onboard. These are satellite communication antennas. They're big so they can grasp even the smallest scrap of a connection and boost it to be heard. Not only are they tunable, but also auto point to maintain the best connection. The small antenna on the phone is multi-directional and has limited power in and out, (think of battery size that fits in one hand and a 500amp battery in the other) the little antenna (that purportedly will give you a brain tumor in 10 years) while a big (6'+) antenna can crank out enough power to fry a chicken in a few minutes. Think if it as an 800watt microwave as opposed to a 1500watt one except multiply it by a factor of 10. It's the story of size matters all over again.
What and absolute complete load of twaddle this is riddled with myth and technical nonsense

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Old 09-01-2011, 18:29   #32
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Is there anyone out there who currently does similar work afloat and can provide some tips?
Mainly we are looking for a semi decent system to transmit data/email either once/twice weekly..
My wife and I both work on board. See my first posting in this thread. There are a number of satellite systems you can install, but the uploads will kill you if there's no payback. We've been using our Iridium 9555 as a modem, but its pretty expensive even if you bundle it up in preloads. Iridium gas a low threshold by the way. This is why we're heading to Hughesnet, as their hardware issues have been modified over the past few months. We have a KVH, but the satellite system (for TV) however internet requires a fairly large antenna that a little pricey, but you pays for what you get. Internet Via Satellite and Phone Service for Boats from TracPhone
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Old 09-01-2011, 18:39   #33
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Originally Posted by Seahunter
One more time:
Think simpler, I have a cell number (MMSI) Bob has a cell number (MMSI) you have a cell phone with an (MMSI). I call Bob on his cell phone. Can you hear our conversation even though you cell is on? NO. Even if you were scanning the station with another SSB it would be too garbled to understand. This is NOT VHF, it's not MF, or HF it's DSC. In order for this to work a separate DSC antenna is required (see Icom 802 installation manual).
Complete nonsense HF/MF and VHF DSC work exactly the same way. They merely cause an alert on the receiving radio ( and in some cases transmit some basic info ). The subsequent voice traffic. Is carried out on normal HF or MF channels DSC does not make the voice call " private" ( or scramble anything) you can listen on any HF or MF set to any voice call initially set up with DSC.

Secondly there is only a few HF equipped rescue centres around the world. In practice programming your sat phone with a major rescue centre like Falmouth in the UK or Halifax or lingby in EUrope is just as good if not better then SSB

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Old 09-01-2011, 18:46   #34
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Originally Posted by Seahunter

My wife and I both work on board. See my first posting in this thread. There are a number of satellite systems you can install, but the uploads will kill you if there's no payback. We've been using our Iridium 9555 as a modem, but its pretty expensive even if you bundle it up in preloads. Iridium gas a low threshold by the way. This is why we're heading to Hughesnet, as their hardware issues have been modified over the past few months. We have a KVH, but the satellite system (for TV) however internet requires a fairly large antenna that a little pricey, but you pays for what you get. Internet Via Satellite and Phone Service for Boats from TracPhone
Sorry seahunter you've missed out the whole range of Inmarsat fleet broadband products which use a new generation of high powered geo stationary birds. The small system FB150 has a tracking antenna that's significantly smaller then most and way smaller then V7 systems which use older low powered birds. ( FB150 equipment costs are similar to good SSb system with pactor and off course at 150kb miles faster ) Despite your previous posts big dishes are used because of the low receiving levels of the signals and not to transmit high power. The larger dish improved both tracking response and allows the receiver operate at the edge of the birds " footprint". The smallest disk has enough transmit power to reach the satellite.

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Old 09-01-2011, 19:24   #35
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Originally Posted by Seahunter View Post
My wife and I both work on board. See my first posting in this thread. There are a number of satellite systems you can install, but the uploads will kill you if there's no payback. We've been using our Iridium 9555 as a modem, but its pretty expensive even if you bundle it up in preloads. Iridium gas a low threshold by the way. This is why we're heading to Hughesnet, as their hardware issues have been modified over the past few months. We have a KVH, but the satellite system (for TV) however internet requires a fairly large antenna that a little pricey, but you pays for what you get. Internet Via Satellite and Phone Service for Boats from TracPhone

Yeah I did look at the KVH systems... their Trac7 is very suitable, but at a quoted cost of "$38,000" its a bit beyond out megre budget... seeing as this is over and above what we paid for the boat even..

A smaller system would be suitable.. seeing as we are only offshore for max 2-3 weeks at a time...
Currently about to set off from Phils to Malaysia and then from Singapore-> Christmas Is and onto Perth/Melbourne... and hopefully continuing onto NZ from there..
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Old 09-01-2011, 19:32   #36
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Originally Posted by Seahunter
Being a DSC radio it requires a MMsi ..... This number can be programed (as well as many others) into the 801 for secure transmissions between ship to ship, ship to shore (CG) or ship to other radios on that ship. The key is that the DSC antenna must be installed properly (see ICOM 801 for IDA-yachts).
Firstly the 801 is a European version of the. 802. The 801 meets ETSI type approval as the 802 did not. Even though the both units are very similar technically. The 801 can act as a DSC class E or A for Carraige required GMDSS ships.

dSC not provide for " secure" transmissions neither the DSC signal nor the subsequent voice traffic is secure and DSC is actually easy to monitor with the right equipment


Quote:
. .... burst transmit an emergency signal with your exact location (GPS connection required) your distress, and the the name of you, your boat, your crew and your MMSI. (which is registered with the FCC and includes information on emergency contacts etc.),
Incorrect there are two DSC emergency scenarios. (1) undesignated distress and ( 2) designated distress. And undesignated distress is generated on pressing the button and the DSC information merely contains the GPS co-ords and the MMSI. In a designated distress the menu system can be used to add a third piece of info , the nature of the distress ( chosen from a preset list )no boat names or crew info is transmitted.

Quote:
Trying to make a sat-phone call in an emergency is not always going to be that easy. Sat-phone coverage is not global and a storm can definitely put a damper on satellite connections, especially with a hand-held.
Not so , iridium is global including both poles an area where HF is difficult to use.

Inmarsat is almost global and covers all the areas to about 60 degrees north it's for practical purposes global( less so globalstar)

Sat phones due to the proximity of LEO birds are not affected by weather HF on the other hand can be severely affected weather.

Quote:
The 801 also has HAM capabilities, albeit limited, however in an emergency HAM operators monitoring the airwaves will be more than happy to offer assistance as is there history.
While the 802 set cab be modified to open up TX on ham bands. I'm not aware that the 801 can be. Such a modification would be specifically illegal on the 801 even with a ham license as the 801 has an ETSI type approval

Quote:
....8However, one needs to remember, unlike commercial ships, airplanes and the like, you'll not have room onboard for a 6+ foot diameter dish antenna for perfect transmission/receive capabilities for your sat-phone, an advantage the 801 has over other VHFs.
Satphones using either inmarsats new generation birds ( isatphone) or any of the LEO orbiting birds in no way needs " 6+ foot" domes the systems are designed to operate fully in spec with internal antennas , domes are use to increase the RX sensibity and are not needed for such sat systems .

PS the 801 is not a "VHF". It's a MF/HF set


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Old 09-01-2011, 19:35   #37
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Here's a link to the first of several USCG videos on DSC.

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Old 09-01-2011, 20:11   #38
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Here's another one from Icom, which demonstrates using DSC to call another vessel:

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Old 09-01-2011, 20:11   #39
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Interesting thread. To go back to the original posters question, $6000 for an SSB system or a sat phone. I think almost everyone under 60 would say the sat phone.

I can't claim personal experience with this, but will pass this on. The person I've hired to maintain my boat in my absence has crossed the Atlantic 15 times, the Pacific 2 times, has 200k blue water miles and another 200k inter-island miles (charter boat captain for 15 years). I have an SSB w/ weatherfax, inmarsat Sat Phone, KVH FB 500, and two VHF's on my boat. He laughed when he saw all this and said his little handheld sat phone was better then all of it. Sat phone and quad band cell phone.

I'm sure there was a time and place for ssb's. Same for land line home phones, desk top computers, VCR's, etc. The fact is that technology is making it archaic.
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Old 09-01-2011, 20:18   #40
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Originally Posted by funjohnson
I have been looking into the globalstar's $20 a month voice, but cannot find anything out about data with that program. Do you know anything about what is included? I emailed two different reps, but they talk about everything but.

I'm mostly looking for email and this seems the least expensive.
If you need a reliable E-mail system you could do worse then consider inmarsats fleetbroad FB150 always on sat system. Uses a very small 11" inch dome rates upto 150kbps compared to 2k using ordinary satphones and about 800 baud using pastor. Also includes a sat phone. Hardware costs around 4 -5 k dollars. With. Voice at $1 a minute and data at $10 a megabyte. Obviously at that price you won't be surfing the web.

In my view ( and as a ham operator myself). Marine HF had a very limited life. All the shipping companies are now using sat systems little traffic uses HF and the number of worldwide HF stations continues. To shrink dramatically ( there's only one in Europe and that merely remains to meet the GMDSS requirements. Telephone interconnects( public correspondence ) had all but been discontinued.

There is no doubt that some life exists on the ham bands. But that really needs dedicated equipment ( I use a icon 706) and requires a degree of technical competence ( as does all HF) and of course there are the commercial restrictions of the amateur radio system

The ARC boats show the way less then 25% have them fitted and nearly 75 % are carrying satphones. A second hand iridium unit can be picked up for 400 dollars. You'd pay for an awful lot of satphone talk airtime with the difference with new HF gear. In the ARC HF is a hobby whereas satphones are the base equipment.

It's also worth noting that HF distress DSC is not without it's problems with the DSC system having to tx on the various HF dsc
channels which can result is a delay in getting out the signal. Equally certainly in Europe the practice has been to confirm DSC alerts via voice hence a SATphone preprogrammed to a major world rescue centre is probably as good and in fact given the technical requirements needed to drive a HF set probably better and easier to use and the likeilihood is in fact it's a better distress alerting system.

It's worth noting that GMDSS did away with the old SOLAS concept of alerting ships in your vicinity. Under GMDSS your equipment should be designed to primarily alert the nearest CG rescue centre. It's then the job of the cG radio to alert rescue alerts in your vicinity. Hence while it doesn't meet the letter of the GMDSS law, it does meet one of GMDSS, s primarily requirements.

It's also worth noting that long range voice systems are not required to meet rescue requirements. Inmarsat C a private non broadcast ( well it does do safetynet) system meets GMDSS requirements . It's entirely likely that in the near future that satphone systems will be integrated into GMDSS. ( I know this is one of the objectives of Inmarsat) this will render marine HF virtually obsolete, since almost exclusively commercial shipping is using sat systems for voice and data and mist large ships merely retain marine MF and HF equipment because they have to meet current GMDSS carriage requirements. The future is undoubtably sat based

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Old 09-01-2011, 20:21   #41
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Originally Posted by Drayla

Yeah I did look at the KVH systems... their Trac7 is very suitable, but at a quoted cost of "$38,000" its a bit beyond out megre budget... seeing as this is over and above what we paid for the boat even..

A smaller system would be suitable.. seeing as we are only offshore for max 2-3 weeks at a time...
Currently about to set off from Phils to Malaysia and then from Singapore-> Christmas Is and onto Perth/Melbourne... and hopefully continuing onto NZ from there..
Fleetbroadband is the way forward not VSAT for small and medium craft

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Old 09-01-2011, 20:39   #42
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Complete nonsense HF/MF and VHF DSC work exactly the same way. They merely cause an alert on the receiving radio ( and in some cases transmit some basic info ). The subsequent voice traffic. Is carried out on normal HF or MF channels DSC does not make the voice call " private" ( or scramble anything) you can listen on any HF or MF set to any voice call initially set up with DSC.

Secondly there is only a few HF equipped rescue centres around the world. In practice programming your sat phone with a major rescue centre like Falmouth in the UK or Halifax or lingby in EUrope is just as good if not better then SSB
Please read:
http://www.cruisersforum.com/forums/...ess-48778.html

One of the nice features of DSC is, if you know the other boats MMSI, to send private messages. In "monitored" waters, this can be a very nice feature. It can take a bit of time to program a message so Twitter/text experience is an asset.

  • Privately hail another DSC equipped vessel, or shore station, with a known MMSI number. Like having a "VHF phone number" this avoids having to monitor high traffic channels just for a hail from your boating buddy. It even "rings" your radio, similar to a telephone, notifying you that you have a call and then switches you automatically to the channel your caller is waiting on.

  • If properly connected to a Loran or GPS, a "Polling" feature transmits your vessel's position, in digital display, that can be monitored by DSC equipped home station/fleet station or boat.


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Even standard VHF can make DSC calls; DSC calls can be made directly to another vessel without broadcasting; it is much more private, like making a phone call. Remember, a DSC call does not use Channel 16. The call can include the channel number on which you want to hold an ordinary conversation.

As far as I found almost every one of the SSB DSC radios built have private channels. It's too bad you didn't read the manual first. Please, do some research. You'll also find that most of Canada, the US and Europe are currently monitored. This is the standard of radios to come. VHF is going to go the way of the CB.
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Old 09-01-2011, 21:17   #43
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Yes, DSC can send private digital messages to other vessels automatically on channel 70, but once you switch to another channel for voice communication, it's all back in the open. Other than the digital messages on channel 70, and automatically switching both radios to another channel, there is not magic here.

Actually, I doubt the messages are really private either -- radios just ignored messages not addressed to their MMSI.
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Old 09-01-2011, 21:23   #44
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Quote:
Originally Posted by Seahunter

Please read:
http://www.cruisersforum.com/forums/...ess-48778.html

One of the nice features of DSC is, if you know the other boats MMSI, to send private messages. In "monitored" waters, this can be a very nice feature. It can take a bit of time to program a message so Twitter/text experience is an asset.

[*]Privately hail another DSC equipped vessel, or shore station, with a known MMSI number. Like having a "VHF phone number" this avoids having to monitor high traffic channels just for a hail from your boating buddy. It even "rings" your radio, similar to a telephone, notifying you that you have a call and then switches you automatically to the channel your caller is waiting on.

[*]If properly connected to a Loran or GPS, a "Polling" feature transmits your vessel's position, in digital display, that can be monitored by DSC equipped home station/fleet station or boat.




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Even standard VHF can make DSC calls; DSC calls can be made directly to another vessel without broadcasting; it is much more private, like making a phone call. Remember, a DSC call does not use Channel 16. The call can include the channel number on which you want to hold an ordinary conversation.

As far as I found almost every one of the SSB DSC radios built have private channels. It's too bad you didn't read the manual first. Please, do some research. You'll also find that most of Canada, the US and Europe are currently monitored. This is the standard of radios to come. VHF is going to go the way of the CB.
I'm sorry I am confused by your response. I am a licensed MF/HF instructor while I don't practice anymore I trained many a ships capitain in DSC.

Firstly DSC isn't private. Neither the digital signal setting up the alert nor the subsequent voice call are in fact private. All dsc does is act as a " ringing signal" in distress cases it carries some extra information.

Note that position reporting , buddy tracking" and any other digital data transfer are outside the international GMDSS specification any there is no certainly that the receipents radio could receive them. Certainly ETSI radios do not have them

Using terms like " privately hail" completely misrepresents why DSC does. DSC merely alerts a receiver to the presence of a sender. Working channel selection is actually being removed from the specifications other then in distress situations as many complaints have arisen over it's use.

Nothing about DSC is like a phone call e in reality the system is not encrypted nor immune from simple decoding. Voice
traffic continues exactly as before.

Note that receiving DSC reporting using a shore station most countries is illegal.

Your comment " even standard VHFs can make DSC calls obviously excludes all those non DSC leisure vhfs out there. ( including the vast majority of handhelds , as there is no agreement about DSC handhelds at this point in time.

Note that no DSC radio has " private channels". There may be in some countries certain reserved channels, but all are accessible. ETSI radios ( the EU standard) do not have any such facility

It's important to realise where DSC cane from and this is an area that US personell are very unclear. DSC was adopted by GMDSS as a way of automating distress procedures along the way the shipping industry grabbed the idea that it could use it to remove the compulsory voice watch ( as did shoreside stations). DSC was then complicated to achieve all this , leading to the nonsense over DSC mayday relay issues. ( and other problems ).

Specifically in relation to MF/HF ( what you call SSB) this is going to be phased out once satphones enter the GMDSS. It is virtually unused commercially and as I said. There is only one HF station in Europe ( Lingby)

Voice VHF will continue to have a long life in port operations close quarter manoeuvres, safety and close range intra and extra vessel communication. It will never go away.

Long range voice over MF and HF has a very limited life. Once the carriage requirements are modified to include sat systems , they'll be dumped overnight and certainly it will not pay companies to produce them for the dwindling leisure sector

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Old 10-01-2011, 16:25   #45
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I reckon that MarkJ means in the previous post is that most of the cruisers gave up on using their HF radios after a short while?

.
Hey matey Hope you are well and enjoying civilization.

What I meant was to show an example occurring 'now' where most cruisers think SSB is irrelevant.
Not only is it not mandatory in these sort of rallys anymore its real usership is down to 50 in 250 ocean crossers.
That really death to that system imho.
I know people in the USA use radios more but the USA is just one isolated country when it comes to world cruising.

As for the DSC baloney sprouted above in some posts, its just drivel.

When we were in the Gulf of Aden needing to speak to the Navy emergency response mob urgently our sat phone call went through instantaneously, clear as a bell, directly into the command center where we wanted it to go.

If you want another example of how useless hf radio is these days listen toi Herb weather on 12359 at 1930 UTC and the word he uses most is "propagation". Chris Parker in the Caribbean was great to listen to between Antigua and St Martin, but only at sea. Get into port and HF dies in the butt from close 'noise'.

I heard a medical difficulty (almost an emergency) on HF on the Atlantic crossing. They had to use Herbs net and the information was relayed through about 3 boats even though those boats were only about 500nms from each other. The information worked and a doctor luckily on another boat was able to help. But with a sat phone it would have occurred in mere minutes, not the hours the relays took. A sat phone emergency room would have got the correct sort of emergency medicine doctor from a major hospital on the phone pronto!

The other bit of misinformation is not having the 'right' number in the sat phone. But sat phones have emergency dialing on 112 (like 911 or 000) you shouldn’t even need a SIM card. The call goes through to the provider of the satellite actually used.

Another point: As long as you have the emergency number of your own government rescue mob, a sat phone will connect you and they can liaise with the correct rescue authority in the country closest to you. on HF you might be stuck trying to translate your call to Indonesian, or Vietnamese. If those countries listen to HF at all. Your own country will ensure the rescue is actually carried too!


A Sat Phone is like a normal Cell Phone. You don't need Acronyms, Abbreviations, Initialization or select frequencies according to sun spots... you just make the friggin' call.
That comes in real handy when a person without a special license needs to get help because the license holder has trapped his finger in the toilet seat.



Its the way of the future

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