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Old 24-05-2014, 15:23   #61
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

After watching all of ka4wja's youTubes, reviewing his prior posts & links, and re-reading the owner's manuals for both my M802 and my VHF (M604) radios, I had the following questions. I hope you guys don't mind a bit more spoon-feeding for a motivated newbie who is trying to learn the basics.

1. On the M802, the manual states that the radio must be set to DSC Watch Mode in order to monitor DSC transmissions, whether they are Distress, Urgent, or Routine calls. Did I read this correctly and, if so, is this your practice while cruising beyond the range of VHF? If wanting only to stay in routine contact with another boat, for e.g., would Watch Mode have to be utilized to receive DSC calls, or would the receiving boat's MMSI number simply be entered and, assuming that boat's radio is turned on, would alert the receiving boat regardless of which frequency it's radio is tuned to?

2. Likewise on a DSC-equipped VHF, does DSC/Ch. 70 have to be phys. monitored to receive routine, urgent, or emerg. DSC calls, or will a DSC call go through if the receiving boat is only monitoring Ch. 16, for e.g.?

3. My M802 manual says that 2187/2182 is the default freq. for 'simple' DSC distress calls. My unit predates the USCG's cessation of monitoring these freqs. by several years. Can this default be changed to one of the other five available freqs. and, if so, which one might be best?

4. John -- in an earlier thread you mentioned that you had no Pactor modem. What do you use for e-mail? I've heard that sound cards can work, but I have thus far not had much luck.

5. Do your Garmin 76ís come equipped with both 12v & NMEA hookups for your radios, or did you have to improvise on the wiring?

6. What type/mfg. of separate antenna would you recommend for full functioning of the DSC on the M802, and where on the boat would you install it? Is it also wired through the auto tuner (AT-140 on my boat)? Is this second antenna the same type as what I have on my masthead for my VHF (Metz)?

Thank you for this and all of the other posted resources. Hopefully one day I'll be in a position to bring someone else along that is similarly new to this.
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Old 24-05-2014, 18:35   #62
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

I'm glad that I've been of help...but reading some your questions, makes me think you should watch a few of them again...


Here are the specific answers in red....
Quote:
Originally Posted by Exile View Post
After watching all of ka4wja's youTubes, reviewing his prior posts & links, and re-reading the owner's manuals for both my M802 and my VHF (M604) radios, I had the following questions. I hope you guys don't mind a bit more spoon-feeding for a motivated newbie who is trying to learn the basics.


1. On the M802, the manual states that the radio must be set to DSC Watch Mode in order to monitor DSC transmissions, whether they are Distress, Urgent, or Routine calls. Did I read this correctly and, if so, is this your practice while cruising beyond the range of VHF?
NO....
No, the manual is confusing...but it doesn't state this....as it states clearly that it is always monitoring the six GMDSS DSC freqs...

As I point out in the videos and is highlighted in the M-802's manual...
The M-802 has a separate dedicated DSC receiver that is ALWAYS monitoring all six GMDSS DSC frequencies, at all tines the radio is turned on....
It does this continuously in the background, and this separate dedicated DSC receiver is NOT affected by any other settings or operation of the radio...
Although in order for this receiver to do its job, it is necessary to have a separate antenna connected to the "DSC antenna jack" on the rear panel of the M-802...
(the only time the average user notices this receiver is working, is when you receive either a DSC Distress Call, or an All-Ships Call such as a "securite" call....but, as long as you have a separate antenna connected to the DSC antenna connector, it IS working!!)


If wanting only to stay in routine contact with another boat, for e.g., would Watch Mode have to be utilized to receive DSC calls,
No, you do NOT need the DSC watch mode to do this....

or would the receiving boat's MMSI number simply be entered and, assuming that boat's radio is turned on, would alert the receiving boat regardless of which frequency it's radio is tuned to?
Assuming the other boat has a separate antenna connected to the DSC Antenna connector, yes this will work fine...

FYI...
When the M-802 was designed affordable sat comm was a dream....and Icom assumed the future was to be all ship's business and public correspondence to be done on HF radio...
So, they designed the "DSC Watch Mode" to allow the radio to be scanning 6 additional DSC freqs (5 of which were duplex shore-to-ship freqs) for calls from shore stations, with routine / ship's business / announcements type calls....

But, this really never came into being used much (aside from some MF stuff)....so the for all pratical purposes the M-802's DSC Watch Mode is not really utilized...
(although, I DID try to encourage its use...by recommending reprogramming the six scan freqs, to other simplex DSC freqs and encouraging cruising vessels to use them.....but this was a rather moot effort, as the little traffic on the GMDSS DSC calling/signaling freqs (which are already monitored by the M-802's dedicated DSC receiver), allows occasional "routine" messages to be sent on these freqs without causing any problems, and nobody needs to do anything to their M-802's to make this work... }



2. Likewise on a DSC-equipped VHF, does DSC/Ch. 70 have to be phys. monitored to receive routine, urgent, or emerg. DSC calls, or will a DSC call go through if the receiving boat is only monitoring Ch. 16, for e.g.?
All Class D VHF-DSC radios (and your M-604 is of course a Class D VHF-DSC radio), have a separate "ch. 70 DSC receiver" built into them and monitor Ch. 70 for DSC calls continuously...just like the M-802 does on HF...
(although unlike the M-802, it use the main VHF antenna to do this, so no separate antenna is required..)



3. My M802 manual says that 2187/2182 is the default freq. for 'simple' DSC distress calls. My unit predates the USCG's cessation of monitoring these freqs. by several years. Can this default be changed to one of the other five available freqs. and, if so, which one might be best?
As has been written before (by me and others), the M-802 manual is pretty crappy (and inaccurate in places), and here it is wrong...
The "default" is 8414.5khz DSC / 8291.0khz Voice...
This is pointed out and shown in the videos...

{BTW, Icom tech support and service has also been ignorant of these facts....that the manual is wrong......and that the "defaults" are 8mhz....
So, use caution when asking them specific questions...}




4. John -- in an earlier thread you mentioned that you had no Pactor modem. What do you use for e-mail? I've heard that sound cards can work, but I have thus far not had much luck.
I have never found the need for e-mail at sea....(and honestly, I find neither do most other cruisers/voyagers...)
I do not need to be "connected" all the time, and actually find the freedom from this to be a big part of the enjoyment of offshore sailing...

{I understand that some cruisers are running businesses while out cruising, and most of them find e-mail necessary for that...but even many of them find whether they have e-mail or not, during the few days / weeks at a time, they are at sea offshore to be inconsequential...}

Is there some reason you have need for e-mail at sea???



5. Do your Garmin 76’s come equipped with both 12v & NMEA hookups for your radios, or did you have to improvise on the wiring?
Garmin sells a data/power cable for about $15....(and I have two of them, one wired and in operation and one spare)



6. What type/mfg. of separate antenna would you recommend for full functioning of the DSC on the M802, and where on the boat would you install it?
What you decide to use a DSC antenna and where you install/mount it, is up to you and depends on your boat...
--Some have found the Metz DSC/WeFax whip antenna (about 49" whip on a small base, which somewhat resembles a marine VHF antenna, but is longer and it is NOT a VHF antenna), to work for them...
--Some have found that the Furuno wefax antennas or wefax whips to work well...
--Some have found using a big 23' whip on their stern to be a great antenna, and this can also be used as a back-up main HF-SSB antenna, should you lose the mast...
--Some have found that using just a wire strung up on a halyard to work for them..
--Some (like me) have found a separate insulated stay (and aft lower shroud in my case) to be a great DSC antenna...(and I also have the Metz wefax/DSC antenna stowed below somewhere as a spare....as it was what I started with as a stern-rail-mounted DSC antenna...)



Is it also wired through the auto tuner (AT-140 on my boat)?
NO...
NO, the separate antenna for DSC reception is connected directly to the M-802's "DSC antenna jack" right on the rear panel of the M-802...



Is this second antenna the same type as what I have on my masthead for my VHF (Metz)?
NO...
NO, you CANNOT use a VHF antenna for HF reception, whether DSC or otherwise!!!


Thank you for this and all of the other posted resources. Hopefully one day I'll be in a position to bring someone else along that is similarly new to this.



I hope this helps..

fair winds...

John
s/v Annie Laurie
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Old 24-05-2014, 20:17   #63
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Quote:
Originally Posted by ka4wja View Post
I'm glad that I've been of help...but reading some your questions, makes me think you should watch a few of them again...


Here are the specific answers in red....





I hope this helps..

fair winds...

John
s/v Annie Laurie

Your answers helped immensely! And yes, I will go watch your videos again. I think there's a saying about how it's better to sound stupid and learn, then try and act smart and stay stupid forever.

My brief replies:

1. DSC & Watch Mode -- OK, I went back to the manual & saw where I screwed up. I also now understand why you didn't mention DSC Watch in your videos. I suppose if you're trying to stay in touch with one or more other boats while on passage, it may be easier to plan to check in via one of the cruiser nets vs. trying to figure out the best frequency to use ahead of time in order to make a direct call, whether by DSC or voice.

2. VHF-DSC -- I thought this was the case on my M604 but got a bit confused after reading the M802 manual I suppose. Thanks for clarifying.

3. DSC Default Distress Frequency -- Good to know the radio is already programmed correctly, but strange that both the manual & Icom tech support remain fouled up on it. (I missed earlier CF threads on this).

4. E-Mail -- Very good point about the necessity for e-mail at sea (i.e. the lack thereof), especially with the widespread availability of internet once in port, and the increasingly affordable options for tracking, texting, etc. if need be. Seems to be a lot of chatter about Pactor modems that I guess I got caught up in, but would love not to spend another $1,000 on more equipment. To the extent it becomes a necessity for work, there is always the sat option which is also becoming more affordable.

5. Portable GPS -- I asked about your Garmin 76 because I think it's a great idea to have an indpt. GPS feeding the radios, along with the utility of an add'l. onboard spare. I have a 376c which has been outstanding but unfortunately doesn't seem to get reception below decks. I also have a 'Colorado' which is preloaded with marine maps, but it unfortunately only runs on batteries. It sounds like the 76 will both run off of 12v and also feed into the NMEA system with the proprietary cord. Good to know.

6. DSC Antenna -- I knew nothing of this until now so appreciate the info. My original installer of my M802 never mentioned this, and never bothered to hook up the radio to GPS! It sounds like there are many different antenna options which I will look into.

You have been most generous with your time, John, and I will continue to study and use my M802 until I am comfortable with it. You are the first radio expert who manages to translate this essential introductory info into plain English, and I am much obliged for your efforts. I hope these and other posts will help others as well, and most importantly provide an additional resource for those like Rebel Heart who may have to avail themselves of their HF radios in less than ideal offshore conditions.

All the Best,
Dan
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Old 26-05-2014, 08:36   #64
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Dan,
I think you're doing great!
Here are just a few more tips and details..


Quote:
Originally Posted by Exile View Post
Your answers helped immensely! And yes, I will go watch your videos again. I think there's a saying about how it's better to sound stupid and learn, then try and act smart and stay stupid forever.
Amen!!


My brief replies:

1. DSC & Watch Mode --
I suppose if you're trying to stay in touch with one or more other boats while on passage, it may be easier to plan to check in via one of the cruiser nets vs. trying to figure out the best frequency to use ahead of time in order to make a direct call, whether by DSC or voice.
a) Actually, in my opinion, the "best" way is to know what would be the best / most appropriate freqs to use for your communications paths...
(yes, these details do come with experience, but the basics are actually pretty easy...)
Two years ago, I wrote a very detailed posting about just this issue...
Please have a look, I think it will clear things up pretty well..

HF Radio Freqs, summertime Atlantic crossing, offshore Net..


b) In general, you can use DSC as a sort of "quasi-ALE" (Automatic Link Establishment), as long as other vessels are so equipped AND have their HF radios turned on all the time....
But, unfortunately most other cruisers will not be leaving their HF radios on 24/7....many due to the power consumption (the M-802 draws about 45 - 48 A/H per day in receive mode, over a 24 hour period), and many out of habit and peace (most do not utilize the voice squelch, which DOES work...nor the DSC Watch Mode)...
So, unless you are a group that has plenty of extra electrical energy on-board, the chances that you'd utilize HF-DSC as an "ALE" system is slim...


c) As I write in the detailed piece, knowing the limitations of both the ionosphere AND our antennas is very important to effective channel/freq choice....since we are using vertical antennas, which are great for long-range sky-wave comms, but horrible for NVIS comms, there may be times that we'll need to use two different bands/freqs to fully cover an area...
But, usually we can make do with one primary and one secondary channel/freq....

My general advice is to always try the highest freq that allows clear communications, as this will have the lowest noise and usually the best s/n...
For "trying to stay in touch with one or more other boats while on passage", what band/freq to use almost entirely depends on the distance between the boats....so, if you are "buddy boating" (NOT my idea of a good thing, BTW) and start a passage together, you will start off very close to each other and will find 4mhz to work well....but as you spread out, you'll probably find 6mhz or even 8mhz to be better....

And certainly if one or the other leaves first, and/or one is staying and one is departing, etc. you will typically be 150 miles farther away everyday!!
So, after day one, daytime comms on 4mhz will be pretty bad, and 6mhz might work thru day two....but I'd simply recommend using 8mhz for ranges from 200 - 600 miles daytime, and 12mhz for 400 out to 1500 - 5000 miles...and 16mhz for 700 - 800 out to 5000 - 6000 miles....(and even 18mhz or 22mhz for these long ranges IF the ionosphere cooperates!)

So in a nutshell:
-- during daytime...if you're within a 100 - 200 miles try 4mhz, 6mhz, or 8mhz....(favor the higher bands first)....and if beyond 200 miles, try 8mhz....and if beyond 600 miles, try 12mhz or 16mhz...
{Generally 8mhz can be thought of as a "Cruiser's Default"... }
-- during evening the range of the these lower bands increases....and the higher bands become unusable (although 12mhz can still be quite strong in the evenings), and as the night continues on, the higher bands become dead and 8mhz ranges are almost worldwide....but you will probably need to use 4mhz (or possibly 6mhz) to actually be able to talk a couple hundred miles....

d) Since most maritime "cruiser's nets" are local/regional, and usually operate with ranges of a few hundred miles, trying to use them when out at sea ("on passage, it may be easier to plan to check in via one of the cruiser nets"), can be problematic at best, and typically not successful...
(although this depends on the net and where your passage is....as the one exception to the above, is the 40m ham "Waterway Net" here along the US East Coast....since they have multiple Net Controllers from the Chspk, Carolinas, Florida, etc. AND ask other stations in out-lying areas to place/listen for calls, the Waterway Net typically covers the entire US East Coast, Northern and Central Bahamas, and some of the Gulf Coast....BUT...But, it is the exception....
There USED TO BE a nice daily long-range / ocean passage Net, that was Herb's Weather Net....and he ran on 12mhz primary w/ 8mgz and 16mhz secondary freqs, and covered the entire N. Atlantic, Caribbean, Gulf of Mexico...as well as the Med and Eastern Pacific, on request or call....but alas he has retired...)

SO...
So, as I wrote above and in detail here ( HF Radio Freqs, summertime Atlantic crossing, offshore Net.. ), knowing what freq to use is the "best" way to utilize your radio....
But in a pinch, try 8mhz up to 500-600 miles away...and 12mhz past 500-600 miles...



4. E-Mail -- Very good point about the necessity for e-mail at sea (i.e. the lack thereof), especially with the widespread availability of internet once in port, and the increasingly affordable options for tracking, texting, etc. if need be.
I have no need to be tracked...but of course we know the NSA is doing it for us anyway....
(my 93 yr. old Mom, and my late father, were longtime cruisers and ocean voyagers....and that was back-in-the-days before GPS, etc...so she has no worries about me at sea, and doesn't expect to hear from me, so when she does it's a nice surprise....but that's it...)


Seems to be a lot of chatter about Pactor modems that I guess I got caught up in, but would love not to spend another $1,000 on more equipment. To the extent it becomes a necessity for work, there is always the sat option which is also becoming more affordable.
Dan, please understand that a PACTOR is actually a GREAT piece of kit!!
They work VERY well, and are extremely reliable...
And, PACTOR-III has better/faster data rates that a "sat phone" data connection...typically 50% - 100% faster....and PACTOR-IV is more than twice as fast as PACTOR-III...
So, should the need for e-mail at sea and/or in remote locales arise for you, I'd recommend a PACTOR-IV "Dragon" modem hands-down above any sat phone connection...
(remember you're not paying by the minute when using PACTOR over HF radio as you do, using data on a sat phone....so it's not just the cost of the PACTOR modem vs. the phone, but also the "airtime" costs that you'll need to figure in...)


Although should you require an "always-on" / broadband internet connection....then it's either Iridium Pilot (~ $4000); INMARSAT Fleet Broadband (~ $5000); or a hi-speed VSAT terminal (~$15,000 - $20,000 and up).....



5. Portable GPS -- I asked about your Garmin 76 because I think it's a great idea to have an indpt. GPS feeding the radios, along with the utility of an add'l. onboard spare. I have a 376c which has been outstanding but unfortunately doesn't seem to get reception below decks. I also have a 'Colorado' which is preloaded with marine maps, but it unfortunately only runs on batteries. It sounds like the 76 will both run off of 12v and also feed into the NMEA system with the proprietary cord. Good to know.
Yeah, the GPS 76 and GPSMap 76 are great units....(I have 3 of the first, and one of the latter....for DSC radios, spare, ditch bag, and dinghy....)
And, how I came upon the use of them for my radios was actually by accident!!
---Just a brief story....In early 2004, I was planning on getting my NMEA position data (for the DSC radios) from my Raymarine GPS (which feeds the instruments, chartplotters, etc.)....but found I would need to either change my system design, or always have either the autopilot or chartplotter on, in order for the radios to have GPS position data...
Well, that was NOT what I desired....so after a few minutes of frustration, I thought "hey, why not just have a dedicated GPS, just for the radios?"....so, that's what I did....(and while I was concerned that I'd have a problem with GPS fix inside the cabin, it turned out the GPS 76 worked GREAT inside...although an old used Lowrance handheld I was given, did NOT...)
Oh, BTW....I came upon the Garmin GPS 76 as my choice by accident as well....it was on sale, so I tried it....it worked...and I've been happy ever since.....
(I wish I could say that "I knew this would all work great, and this was the way I had planned it all along"....but alas, that would be a lie....even though I've made my living in sat comm, I did not do a GPS link analysis, nor did I research which GPS chips would work best inside the cabin, both things I could have easily done....no, I took the easy way out, I got lucky!!
So, my luck is other's gain!!)




6. DSC Antenna -- I knew nothing of this until now so appreciate the info. My original installer of my M802 never mentioned this, and never bothered to hook up the radio to GPS! It sounds like there are many different antenna options which I will look into.
After majoring in physics, but not wanting to work in that field, I've made my living in electronics for decades....I've owned/operated my own electronics / sat comm firm, for over 30 years now....specializing in commercial sat comm for the past 20+ years now...(not to mention my 40 years of non-professional experience in RF communications in general and HF / VHF / UHF comms in particular...)
And, although I do NOT sell/install marine electronics for a living (it's just a hobby), I am constantly amazed at the majority of guys doing it that are completely ignorant of even the basics and totally incompetent!!!
Sorry to be so blunt, but 99% of these guys are barely qualified to put batteries in a flashlight....yet they pass a test, or take a class, and "poof" they're an "expert"....God, it makes me sick!!!


You have been most generous with your time, John, and I will continue to study and use my M802 until I am comfortable with it. You are the first radio expert who manages to translate this essential introductory info into plain English, and I am much obliged for your efforts.
You/re very welcome....

But, FYI, when talking with friends (many of whom are RF engineers / comm engineers by profession), we ramble on about esoteric things that make others eyes roll, etc.
I've had 2 - 3 hour long conversations on-the-air dealing with one minute technical issue....and have others break in and ask if I was an engineering professor.... ..... so be happy that you aren't to well versed on some of this, otherwise you'd get a real headful of stuff, and not in "plain English"!!
How about a discussion of simple negative feedback circuitry for transmit PA's that is temp stable??? Ohhhh, that sounds like we could chew on that one for hours, huh??? Or maybe we should talk about adjusting antenna height to move our radiation lobes/nulls to better suit the ionosphere of the moment??? Or how about ionospheric soundings and how can be better utilize them to maximize out signals at specific distances??? (this is one I was planning on discussing a few weeks ago, but got waylaid by some family matters)
Like I said be happy you caught speaking plain English...


I hope these and other posts will help others as well, and most importantly provide an additional resource for those like Rebel Heart who may have to avail themselves of their HF radios in less than ideal offshore conditions.
While I do hope this does help everyone that reads/watches....I'm realistic enough to understand a few simple facts of life...
--- The smartest people I know, ask questions and admit what they don't know...
--- The internet spreads and encourages big egos....and the more you read/post, the more you think you know...
And, the fact that NOBODY knows everything, seems to be lost amongst internet posters.....
(and I'm no different, I've been known to become pretty strident in my words and take umbrage at some comments that I see as insulting to my knowledge/expertise...letting my ego type rather than my brain... )

So, while I stand behind my words 100%, please remember I am human and imperfect, just like everyone else....and use caution when one person tells 'ya something....
They might be 100% correct, but do some independent research as well....not just 'cause it'll back-up the advice you've been give, but also because you'll gain a deeper understanding of the issue...

Fair winds...

John
s/v Annie Laurie

P.S. There is another old posting of mine that might be of some help to others...
Tips for using an HF-SSB Radio (mostly for newcomers)
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Old 26-05-2014, 12:13   #65
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

The theories are nice, but there's one problem with trying a half dozen different high frequencies in order to reach a buddy (etc) whether you have sailed apart or one has remained in port.

While you're trying to call them, let's say, 12-8-6-4 for thirty seconds or a minute or even two minutes, they may be cycling frequencies one step off. Or in the reverse order. Or, just monitoring one which isn't going to work. You are both moving targets when you are cycling through different frequencies, and two moving targets [sic] makes it much more difficult to "hit" the other one.

Then of course even with modern $10 quartz accuracy...if you're on the same schedule, are you both really still paying attention to keeping good time on your Casio? Or are you the minute or two apart on that as well?

Not that it can't be done by two co-ordinated sailors who understand their gear and how to use it, together. But for one-to-one communications, I think this is all part of why satcoms attract more interest. Pick up phone, punch number, ignore that pesky man behind the curtain. And, ignore that incredible globe-circling infrastructure. (Which really SHOULD boggle one's mind.)

Even one vessel equipped with an NVIS antenna will be useless--since the other vessel probably isn't equipped that way, so again, the coms will only go one way.

HF is still very useful, but "horses for course" still applies. And in this case, horse plus trained jockey applies.
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Old 26-05-2014, 13:32   #66
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Yep, hellosailor is quite right about trying to hit a "moving target"....which is why I always recommend ONE primary freq to be used / tried for a set period of time such as 15 minutes, 30 minutes, etc....and if no contact is established ONE secondary freq to be used for the same amount of time, immediately following the prescribed first freq time period...

I've ran skeds on HF for decades and unless someone forgets to show up, or they've been injured in an accident, I've never failed to make contact...ever...

And, while sat comms is okay for a one-to-one conversation.....the HF radio is the only way to talk/raise multiple people, over vast distances...



Fair winds...

John
s/v Annie Laurie
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Old 26-05-2014, 17:13   #67
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

That was an instructive primer on how to use different freqs. which will help me start the learning process I'm sure. With regard to establishing comms. with individual boats, I was mainly thinking about the feasibility of sharing info -- primarily about weather & sea conditions -- with boats that are ahead or behind but on a similar course. I remember reading somewhere that when Herb was still broadcasting, he would facilitate some airtime following his regular report for boats (that had checked in) to communicate with each other. It sounds like he had far-reaching transmission capabilities, however, whereas some of these other nets I read about may not. Communicating directly no doubt requires a higher proficiency level, but would be informative and fun if I could ever pull it off.

Given the power demands and other factors, continuously monitoring the 6 (now effectively 5) emerg. DSC stations doesn't seem to have the same legal or even ethical impetus that monitoring Ch. 16 on VHF entails. I would be inclined to do it in any event on a long passage, but I have plenty of reserve power and numerous ways to regenerate. Is this what you did on your trans-Atlantics, John, or did you need to conserve power? Aside from emerg. monitoring, I can only imagine the interesting & far-reaching communications you could pull off mid-ocean.

Understood -- about the Pactor modems that is. I had actually owned my Iridium phone for a couple of years before acquiring the boat. I initially bought it for a long, remote dirt bike ride along the 'Trans-America Trail' from New Mexico to Port Orford, Oregon. Thus far I've only had need for their lowest-priced, emerg. subscription, but had always assumed I would sign up for e-mail & weather subscriptions once I began serious cruising. Now I'll reconsider given the potential of the M802. I had erroneously thought, btw, that one could only receive weather fax via a Pactor, so nice to know the modem is apparently only necessary for e-mail at sea should that be desired. With the new & improved Pactor IV Dragon, maybe I'll get lucky on a reasonable price for a used III or even II. Even if I decide that e-mail at sea is necessary or desirable, I doubt that speed would become that big of a priority. Any thoughts?

Very good point about the redundancy your 76 provides for maintaining GPS for your radios in the event your primary GPS system suffers a failure, or if you simply want to turn it off as you mentioned. Like you, I keep my Garmin 'Colorado' in the ditch bag with a ziploc full of spare batts., and also use it for the dinghy since it stays loaded with both marine & street maps. Most handy when landing the dink on unknown shores!

Yes, in hindsight it is quite odd that the original installer failed to connect my M802 to GPS (my VHF always had been), or at least inquire about the second antenna for DSC. After the fact, I did have the good fortune of hooking up with Bill Trayfors while anchored in the Wash. Channel one summer, after watching a SCCA webinar that he did. Bill came aboard, had me rewire the 802 direct to the ship's battery bank, tested the system for adequate grounding, and even left behind a small computer fan that I installed to keep things cooler in my rather cramped & hot electronics locker! And oh yeah, there were a few cocktails at the nearby Capitol Yacht club too.

Too funny about the radio lexicon & lingo. I enjoyed an earlier post about Ham radio guys liking nothing better than to be interrupted with an emerg. from a sailor at sea from their nonstop talk about gall bladder surgeries and antenna tweaks. The plain English has been a godsend for me, but I'm sure you must have to concentrate that much harder! As it is, the recent, brief exchange b'twn. you & hellosailor had me Googling "NVIS" antennas. I'm still at a loss with your reference to "skeds," but probably not too critical.

I'm off to check out your most recent set of links, and to finish re-watching your vids! Probably only to return with yet more questions . . . .

Many thanks . . . again!

Dan
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Old 26-05-2014, 18:46   #68
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Dan,
You're very welcome....

In "general", for the application you mention....try 8mhz, primary....8.294mhz...(channel "8a")...and 6mhz secondary....
(if you spread out farther than 600 miles, then try 12mhz primary with 8mhz secondary...)



Quote:
Originally Posted by Exile View Post
...when Herb was still broadcasting.... It sounds like he had far-reaching transmission capabilities, however, whereas some of these other nets I read about may not.
Yes and no....
Yes, Herb had a "decent" set-up, and yes, most of the other maritime nets (not the 40m Waterway net, nor the 20m MMSN), don't have anything except their radios / backstays on-board (or possibly just a simple shore-side antenna)...

But, no...
No, a LOT of the excellent results Herb had over 25 years of daily Net operations were do to 2 main factors....
a) His choice of freq/channel to cover the whole N. Atlantic...and a decent / basic understanding of radiowave propagation...
b) Decades of experience on-the-air....

I've tried to stress this before.....but many cruisers/sailors will spend 1000's of dollars and many hours taking classes / seminars, about diesel engine maintenance; navigation; sail handling and vessel maneuvers; foreign languages; first aide; SCUBA; etc. etc...but decide not to bother to learn about radiowave propagation or radio operating procedures????
Still make me go, huh???



Given the power demands and other factors, continuously monitoring the 6 (now effectively 5) emerg. DSC stations doesn't seem to have the same legal or even ethical impetus that monitoring Ch. 16 on VHF entails.
Yes....except that it is still 6 freqs....just 'cause the USCG, Aus Maritime Auth, etc. don't monitor MF (2187.5khz DSC), it doesn't mean that it isn't used/monitored, because it actually IS monitored by all SOLAS vessels, as well as > 450 coast stations worldwide....


I would be inclined to do it in any event on a long passage, but I have plenty of reserve power and numerous ways to regenerate. Is this what you did on your trans-Atlantics, John, or did you need to conserve power?
No, I don't run the HF rig 24/7 at sea....(520 watts of solar, a towed-water gen, big batteries, etc...but still don't leave the M-802 on, unless I'm using it or getting ready to..)

Aside from emerg. monitoring, I can only imagine the interesting & far-reaching communications you could pull off mid-ocean.
Actually had the crap scared out of me, sitting at the Nav Station listening to the BBC News (?) on the M-802, with my headphones on, at night, tied to the quay in-port in Horta, Azores....when a DSC-Distress alert was sent out, and the M-802 alarm sounded and jolted me almost out of my seat!!!
Surprisingly, most of my DSC receptions have been at the dock, or at anchor, when I'm on the radio more...



With the new & improved Pactor IV Dragon, maybe I'll get lucky on a reasonable price for a used III or even II. Even if I decide that e-mail at sea is necessary or desirable, I doubt that speed would become that big of a priority. Any thoughts?
I've seen used PTC-IIe modems sell for about $600 - $700....



Very good point about the redundancy your 76 provides for maintaining GPS for your radios in the event your primary GPS system suffers a failure, or if you simply want to turn it off as you mentioned.
Actually never use the chartplotters (E-120 and E-80) at sea, unless I'm using the radar to find the heavy squalls....
It's just a main Raymarine GPS, the Garmin 76, and now my Emtrak AIS GPS.....
Oh, and yes I'm an odd-man out around most discussions here abouts....as I use paper charts (and guide book chartlets) as my primary, with the Navionics in the plotters as secondary...and regularly plot my positions on these charts....(and I even have a Tamaya sextant, almanac, and tables on-board, but these are mostly for fun these days... )



After the fact, I did have the good fortune of hooking up with Bill Trayfors while anchored in the Wash. Channel one summer, after watching a SCCA webinar that he did. Bill came aboard, had me rewire the 802 direct to the ship's battery bank, tested the system for adequate grounding, and even left behind a small computer fan that I installed to keep things cooler in my rather cramped & hot electronics locker! And oh yeah, there were a few cocktails at the nearby Capitol Yacht club too.
Bill's a good guy (how could I write anything else here...
And, you are very lucky to have found him!!!



As it is, the recent, brief exchange b'twn. you & hellosailor had me Googling "NVIS" antennas. I'm still at a loss with your reference to "skeds," but probably not too critical.
Use caution when looking up NVIS antennas, as there is a LOT of misinformation out there....(in general, a horiz dipole at 0.2 wavelengths high is the standard that NVIS antennas are measured against....but an "Extended Lazy-H" can be even 6db better, if you have the room!!!)
Reading up on an "extended lazy-H" won't do you any good for your on-board communications...but, if you get bored some night....



Oh, and a "sked" is communications-speak for "schedule"....
i.e. "a sked @ 0200z on 3660+/-", means meet the other station at 0200 UTC/GMT, on 3.660mhz LSB, and move up or down up to 5khz away (3.655mhz to 3.665mhz) to find a clear frequency....


I'm off to check out your most recent set of links, and to finish re-watching your vids! Probably only to return with yet more questions . . . .
Study hard....there is a test at the end of the week...


Fair winds...

John
s/v Annie Laurie
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Old 26-05-2014, 20:44   #69
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Given the power demands and other factors, continuously monitoring the 6 (now effectively 5) emerg. DSC stations doesn't seem to have the same legal or even ethical impetus that monitoring Ch. 16 on VHF entails.
Yes....except that it is still 6 freqs....just 'cause the USCG, Aus Maritime Auth, etc. don't monitor MF (2187.5khz DSC), it doesn't mean that it isn't used/monitored, because it actually IS monitored by all SOLAS vessels, as well as > 450 coast stations worldwide....

Ok, got it.


I would be inclined to do it in any event on a long passage, but I have plenty of reserve power and numerous ways to regenerate. Is this what you did on your trans-Atlantics, John, or did you need to conserve power?
No, I don't run the HF rig 24/7 at sea....(520 watts of solar, a towed-water gen, big batteries, etc...but still don't leave the M-802 on, unless I'm using it or getting ready to..)

Off-topic, but what type of towed water gen do you use, or did you devise your own? These have always impressed me for their efficiency, but people report problems, and I definitely can't afford the $7K Watt&Sea!


Very good point about the redundancy your 76 provides for maintaining GPS for your radios in the event your primary GPS system suffers a failure, or if you simply want to turn it off as you mentioned.
Actually never use the chartplotters (E-120 and E-80) at sea, unless I'm using the radar to find the heavy squalls....
It's just a main Raymarine GPS, the Garmin 76, and now my Emtrak AIS GPS.....
Oh, and yes I'm an odd-man out around most discussions here abouts....as I use paper charts (and guide book chartlets) as my primary, with the Navionics in the plotters as secondary...and regularly plot my positions on these charts....(and I even have a Tamaya sextant, almanac, and tables on-board, but these are mostly for fun these days... )


Without much of a background, I'm more chart plotter dependent, but I admire and indeed envy the skills you mention. Whenever I'm out of sight of land, I always plot my position on paper charts, usually no less than every couple of hours. I do, however, use my chart plotter to obtain those positions! Unlike other sailors I've read about in recent years, I personally would never dream of leaving port without a reasonably updated set of paper charts, no matter where or how far I'm sailing. But to each his own, I suppose. I also have a "starter" sextant, but I have to confess it hasn't made it out of the box yet. All in good time, but first the M802 and maybe a Ham license down the road.


After the fact, I did have the good fortune of hooking up with Bill Trayfors while anchored in the Wash. Channel one summer, after watching a SCCA webinar that he did. Bill came aboard, had me rewire the 802 direct to the ship's battery bank, tested the system for adequate grounding, and even left behind a small computer fan that I installed to keep things cooler in my rather cramped & hot electronics locker! And oh yeah, there were a few cocktails at the nearby Capitol Yacht club too.
Bill's a good guy (how could I write anything else here...
And, you are very lucky to have found him!!!


We'll have to talk about Bill T. later and in private, behind his back, of course. Kidding aside, I was lucky indeed, and we had some fun too. Bill's own sailboat is very interesting, btw.


As it is, the recent, brief exchange b'twn. you & hellosailor had me googling "NVIS" antennas. I'm still at a loss with your reference to "skeds," but probably not too critical.
Use caution when looking up NVIS antennas, as there is a LOT of misinformation out there....(in general, a horiz dipole at 0.2 wavelengths high is the standard that NVIS antennas are measured against....but an "Extended Lazy-H" can be even 6db better, if you have the room!!!)
Reading up on an "extended lazy-H" won't do you any good for your on-board communications...but, if you get bored some night....


Oh boy, here we go . . . . Is there one of these little smiley icons for eyes glassing over??!


Oh, and a "sked" is communications-speak for "schedule"....
i.e. "a sked @ 0200z on 3660+/-", means meet the other station at 0200 UTC/GMT, on 3.660mhz LSB, and move up or down up to 5khz away (3.655mhz to 3.665mhz) to find a clear frequency....


That one actually wasn't too bad. I understood it, believe it or not.

But here's a dumb one that I don't quite understand (believe it or not). Is every freq., for e.g. 3.665mhz as you reference above, either LSB or USB (let's leave the other bands aside for now)? In other words, are there freqs. which appear on both LSB and USB, or do they only appear on one band or the other?

And if you thought that one was dumb, this one's even dumber. Is, as I assume, the frequent reference to "meter" when referring to any particular freq. level the same as mhz? In other words, is 8.294mhz a freq. within the "8-meter" band, along with every other frequency that is 8mhz? As you've probably figured out by now, I'm not shy about publicly embarrassing myself in exchange for a little more knowledge, and I've had trouble figuring these out from the "Idiot" guides. My oversight to be sure.



Study hard....there is a test at the end of the week...

In that case, I'm definitely screwed. How about towards the end of the month following the month after next?!
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Old 27-05-2014, 10:14   #70
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Quote:
Originally Posted by Exile View Post
Off-topic, but what type of towed water gen do you use, or did you devise your own? These have always impressed me for their efficiency, but people report problems, and I definitely can't afford the $7K Watt&Sea!

I tow a Hamilton Ferris WP-200....
It works very well....only trouble I've had is some line chafe, due to my initial mounting angle (since modified)....
At speeds > 3.5 kts, I get about 1.1 to 1.4 amps per knot of boat speed....with typical sailing speeds on long passages averaging 6.5 - 7.5 kts, that's about 8 - 9 amps of charging average over 24 hours....giving me ~200 A/H per day of charging, when on a long passage....(but usually only deploy it if it's cloudy...)

I wrote a brief article on it....and have posted here about it as well...(do a search here for "towed-water generator")

And, have a look here...
Towed-Water-Generator







But here's a dumb one that I don't quite understand (believe it or not). Is every freq., for e.g. 3.665mhz as you reference above, either LSB or USB (let's leave the other bands aside for now)? In other words, are there freqs. which appear on both LSB and USB, or do they only appear on one band or the other?
Uhhh...well don't have the time to go into details now...best you study for your ham license and you'll learn a lot about this...
But, 'til then....
Wahtever freq the radio is tuned to, is the "carrier" frequency, and in SSB mode (Single Side Band), the "carrier" is suppressed and you can choose either the Upper Side Band (USB), or Lower Side Band (LSB), for where you want your signal (Voice) to sent....
A USB signal would extend above the carrier freq and the LSB signal would be below the carrier freq...

In marine HF SBB service the channels are spaced 3khz (or .003mhz) apart, but in the HF amateur radio service (HF Ham radio), there are NO "channels", so it is up to the operators to space themselves out accordingly, using "good engineering" and "good amateur practice" (exact wording of the laws/rules governing ham radio)....and on most days, most hams try to stay about 3khz (2.5 - 5khz) away from each other...but on crowded days, such as when radiosport contests are on-the-air, you'll find hams trying to squeeze in with barely 1khz - 1.5khz spacing....

So, if you had some stations using 3.665, and others on 3.662, and others on 3.668....all is well....IF they are all using the same sideband (which they all do)!!!
If you had some guys on 3.665 LSB, and then some on 3.662 decided to use USB, BOTH of these groups of stations would be occupying the same narrow set of frequencies (they would be using the same "passband"), but their signals would be inverted and would sound completely unintelligible (this audio inversion is still used as a cheap form of "scrambling" / "encryption" by some commercial radio users...) and the guys on 3.665 would be VERY pissed off!!!

As for "which sideband to use"????
That's actually VERY easy....
ALL maritime, aviation, US gov't, ALL commercial HF users in the US, etc. and almost all commercial and gov't users worldwide use USB, Upper Side Band....
But...

But, hams are different.....
By MUTUAL GENTELMEN'S AGREEMENT (not by law), 99.999999999% of all ham radio SSB comms follow this basic rule, worldwide...
All SSB comms BELOW 14mhz is LSB....
All SSB comms AVOVE 7.3mhz is USB...
(And all ham radios made in the past 30 -40 years have this as their default setting...)
The reason for this is OLD....it is just a hold-over from the early days of ham radio Single Side Band communications / transmitters....the original ones from the 1940's and 50's (either home-made, military surplus, or commercially made), used a 9mhz IF frequency....so as the LO freq was changed to generate the signal on whatever band/freq you desired, on bands below 9mhz, you had a LSB signal thru one filter and on bands above 9mhz, you had a USB signal thru the filter...
It was a cheap and effective way to cleanly generate a suppressed carrier SSB signal.....
And, this "anomaly" of ham radio is still with us today....more than 60 years later....




[Note there is also something called ISB, Independent Side Band...where DIFFERENT information is sent out on LSB and USB....although not used much anymore, in years past this was common for gov'ts and commercial HF users to send Voice on one (USB), and test/teletype on the other (LSB), at the same time....and the transmitters / amplifiers spec'd for ISB were quite expensive, and VERY clean, as they needed to maintain superior linearity...]



And if you thought that one was dumb, this one's even dumber. Is, as I assume, the frequent reference to "meter" when referring to any particular freq. level the same as mhz? In other words, is 8.294mhz a freq. within the "8-meter" band, along with every other frequency that is 8mhz?
Hams and "shortwave broadcasters" are probably about the only ones that still use the "wavelength" to refer to specific bands/signals, etc....(such as the 40 meter ham band, or the 20 meter band, etc.)

---This is simply the wavelength of the signal....(how long one complete "cycle" takes)

---The "frequency" is how fast the signal is "vibrating"....

Think of big rubber band, or bungee cord....
Stretch it out from your mast to the cockpit, so it is somewhat tight (NOT drooping)....
Pluck it or whip it, hard, like it was a big guitar string....
You'll see it vibrate.....
---The "frequency" of its vibration is the frequency of the "wave"...
---The length / spacing of the "wave" is wavelength....
You'll note that the faster you make the vibration/wave (increase its frequency), then the shorter the wave gets....and vice versa, as the wave gets shorter, it's frequency increases....
And, this is the relationship between frequency and wavelength....

You can also think of ocean waves....the shorter the "wave period" (short wavelength), then the faster the frequency of the waves (the quicker they hit 'ya)....not as good of an explanation....but I hope you understand...

So, if I refer to 7.268mhz....that is the same as 7268khz....and that "frequency" is in the "40 meter ham radio band"....
14.300mhz is 14300khz, and it is in the 20m ham band....

As I wrote hams are about the only ones still referring to the wavelengths these days....so, for maritime operations, just refer to the "band" in its general frequency range, such as 8.294mhz is in the "8mhz marine band"....
(and yes, I often intersperse kHz and MHz in the same conversation, and sometimes in the same sentence, when speaking casually....so if you see/hear me say "8294 kilo hertz" or "8294 mega hertz", understand that while I may forget to speak the decimal point, I AM referring to the same frequency....sometimes I just ramble on too fast.... )




As you've probably figured out by now, I'm not shy about publicly embarrassing myself in exchange for a little more knowledge, and I've had trouble figuring these out from the "Idiot" guides. My oversight to be sure.
I don't wish to be rude to some of those authors....but many times I think "idiots guides" are describing the authors, NOT the readers....

Fair winds..

John
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Old 28-05-2014, 11:19   #71
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Nice article & pics on the water generator, John. Although actual output may be less than mfg. specs, it still seems realistic to meet daily needs, even on my power-hungry boat. I am inclined to start off with solar panels, but don't care for the wind gens and so the water gen would likely be my next step. While exorbitant, the Watt&Sea really has great reviews. Coincidentally, I happened to see the prototypes on Brad Van Liew's Velux5 boat some years back in Charleston. At that time, the hurdle was being able to properly regulate all of the excess amperage being generated!

Whoa! Your responses strongly suggest that my questions about USB/LSB & "meter" bands weren't so stupid after all! It sounds like I'd be well-served -- at least before I graduate from my elementary school education on all this -- to forget about these two issues for awhile. Best wait 'til I start junior high . . . if not high school.

Reading through your SCCA links now . . . .
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Old 28-05-2014, 11:30   #72
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Informative & entertaining article about the sort of boat-to-boat comms. that are feasible with HF radio (in the right hands) on long passages:

Info and entertainment at sea - Ocean Navigator - July/August 2013


If Iridium's claims are accurate, this latest sat comm. device looks to be somewhat of a game changer compared to what's out there. No internet, but easy e-mail, text, and voice comms. at competitive rates, all conveniently paired through the user's own cell phone, tablet, or computer. Supposed to be released next month:

The ultimate Wi-Fi hotspot - Ocean Navigator - Web Exclusives 2014
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Old 29-05-2014, 00:26   #73
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Dan,
I'm glad you found that Ocean Navigator article interesting and helpful....
(and, I hope you don't mind if I blow my own horn a bit??)
Quote:
Originally Posted by Exile View Post
Informative & entertaining article about the sort of boat-to-boat comms. that are feasible with HF radio (in the right hands) on long passages:

Info and entertainment at sea - Ocean Navigator - July/August 2013
Because it was my original posting on the OCC and SSCA disc boards, from early 2012, that gave the author the technical info (and motivation?) to start / run their own net....


Have you read it??
HF Radio Freqs, summertime Atlantic crossing, offshore Net..




Fair winds...

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Old 29-05-2014, 11:45   #74
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

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Dan,
I'm glad you found that Ocean Navigator article interesting and helpful....
(and, I hope you don't mind if I blow my own horn a bit??)
Because it was my original posting on the OCC and SSCA disc boards, from early 2012, that gave the author the technical info (and motivation?) to start / run their own net....


Have you read it??
HF Radio Freqs, summertime Atlantic crossing, offshore Net..




Fair winds...

John
s/v Annie Laurie
Why am I not surprised that you also helped out the Pacific cruisers who wound up writing the article in Ocean Nav?! The more links/reading/info you provide, the more I learn! But whether I become "educated" is the lingering question, I suppose . . . .

Since you are involved in the biz, any thoughts on the soon to be released Iridium 'GO'? Although my old 9555 will accomplish the same voice & data comms., I like that this new model will facilitate this through one's own smartphone/tablet/computer, and thus presumably doesn't entail any configuring, adapters, Euro-based phone nos., etc. It also sounds like the initial hardware cost and subscription rates will be comparable.

In my mind, this would still only serve as an alternative/backup to HF radio at sea. "Conference" calling by satphone every day by those Pacific cruisers all the way to the Marquesas -- even if feasible -- would have been just a tad expensive, no?

Dan
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Old 29-05-2014, 13:35   #75
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Re: Advisability of Depending on Satellite Comms & Knowing the Transmitter Works

Dan,
The Iridium GO, is a cool piece of gear....although I'v not personally seen/used it, it seems like it is even better than "plug-'n-play", as there is no "plugging" needed...
Quote:
Originally Posted by Exile View Post
Since you are involved in the biz, any thoughts on the soon to be released Iridium 'GO'? Although my old 9555 will accomplish the same voice & data comms., I like that this new model will facilitate this through one's own smartphone/tablet/computer, and thus presumably doesn't entail any configuring, adapters, Euro-based phone nos., etc. It also sounds like the initial hardware cost and subscription rates will be comparable.
But while you grasp that it is still low-speed data to/from the satellite, and this limits you to e-mail, text, SMS, etc...I hope others understand that...

Also, I hope that whatever Smartphone Apps, messaging, etc. people utilize thru it, will not chew up all their data availability/air-time???
I can just see folks getting BIG bills for their month usage and not realizing what they are spending 'til they get the bill....
(this has happened to a LOT of users of INMARSAT FB, Iridium Pilot, etc....where "always-on" internet just keeps on going, updating, checking mail, playing music, etc. even with nobody at the keyboard....I've heard of a few dozen FB users whose first monthly bill was almost $5k....and I think INMARSAT did what most phone companies do, they gave 'em a ONE-TIME credit and told them how not to get hit with the big bill again...)


Also, since I haven't seen the GO yet, I don't know rugged/weather-proof it is?? So, wondering if it'll survive well in the cockpit / under the dodger at sea....or is it going to be something that most will only use in calm weather or at anchor???


Sorry about all my ????, but I haven't seen it yet...


Fair winds.

John
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