RFI-EMI-GUY
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Your $200 marine radio is now $1200. You are welcome.
Marine band going digital
- Thread starter Monitorman7001
- Start date
Your $200 marine radio is now $1200. You are welcome.
RFI-EMI-GUY
Member
- Joined
- Dec 22, 2013
- Messages
- 7,515
Unfortunately engineers are as guilty as anyone for blindly chasing trends. Who can blame them, if you are not writing new standards for some crazy radio system, you will be out of a job, or demoted to designing lamp fixtures.
IMO and observations while monitoring ships and the coast guard in Duluth MN from 2010-2011 vhf analog works better in very fringe areas. Even if a distorted weak signal is received in analog on the seas one may or might likely decipher live saving information in some extreme situations, or some words in the analog transmission compared to a weak and faded digital signal like on the MN ARMER https://www.radioreference.com/apps/db/?sid=3508 system that gets garbled due to range limitations. That extra weak analog signal in the fringe distorted area may be readable. Digital just cuts off at certain ranges with no hope to receive it beyond a certain point. The analog signal may make the difference between life and death on a boat in distress and may better help save a crew in distress. This is the one place I think analog radio should stay analog. Im not a radio expert nor have I served in the honorable life saving coasties! Cheers mate for your dedicated years in life saving service to your county!! But I do remember when on my M1A1tank that we had way less range on our SINGARs radios when we encrypted them compared to when we we stayed analog in the clear.
mmckenna
I ♥ Ø
Thanks,
There's a lot to unpack with this thread, not your post, but the entire thread in general. This has become humorous because of the assumptions and sweeping generalizations made by those that are very clearly not experienced setting up digital radio systems. CCR digital radios don't count, and using them as the bench mark for digital radio systems, and the cornerstone of an argument against digital, it verging on pure comedy. I really do try to treat people equally here, but there comes a point where the basis of the argument is just so flawed, it's not worth my time and effort to drag it back on course.
Basing the digital/analog argument off radios that were set up by someone else who may or may not have been experienced isn't much better. Simply picking up a digital radio and using it doesn't make for a solid footing for the argument.
Analog works very well, but there's a whole lot more to making radios work well outside the modulation method involved.
I've run Analog wide and narrow systems along side DMR, P25 and NXDN in real world environments, including setting up and aligning complete systems myself. Not amateur radio systems, but actual public safety (fire and sworn PD) systems.
There are some skills involved that go beyond the 35 question multiple choice amateur radio test. While I'm a ham myself, and have been for several decades, there's a difference between the hobby radio and the professional/paying radio work.
Like I said, I've run these systems side by side. By "run", I mean I align radios. I set up and entire NXDN trunked system from scratch. I tested the system, conferred with the manufacturer, and spent a lot of time adjusting the audio settings to make it work right. That took weeks. Not hours.
Modern digital radio systems can work as well and in some cases better than contemporary analog systems. I've done it. I've tested them in controlled environments.
The range argument involves a lot of variables that a simple end user of a digital radio won't necessarily have control over.
I took a 5 channel analog trunked system running 25KHz wide 800MHz channels and swapped out 2 of the analog repeaters with digital NXDN repeaters. That was same site, same combiners, same coax, same antennas. That let me test analog side by side with digital in a controlled situation. The difference is very close, but a properly designed and set up digital system will get a bit more range than analog. Recovering 1's and 0's out of the noise isn't hard. The recovered audio will be clean, until it's not. But that recovered digital audio will be useable when the analog signal gets so bad that the human brain cannot pull coherent sentences out of it.
Been there, done that, got the t-shirt. This wasn't someones amateur radio repeater. This wasn't a retail store radio. This wasn't something that someone slapped together to pull a project in under budget. This was me doing it, having all the time I needed to make it right.
And ITU will do the same thing. They are not pulling a standard out of a hat and assigning marine radios to use it. It's a process that will involve a lot of testing. That was covered in the article (that I think most commenters haven't read). All one has to do is see what's been done with the AIS systems bouncing digital signals around with a few watts on VHF marine channels. I have an AIS receiver at one of my high sites, and I very regularly get hundreds of miles of range out of an AIS burst. Best I've done so far was 750 miles. Analog won't do that with a recoverable signal.
And there are some really good benefits to digital when compared to analog. Again, the ITU covered that well in their documents. The ability to forward packets from radio to radio when needed to extend range. True data capability. Native radio ID for each and every transmission. Ability to tag all traffic with lat/lon. Navigation data. Warnings. Localized weather alerts. A lot of things that are not currently done on analog.
At no point did they claim that there would be a slash-cut to digital, leaving everyone out in the cold. There is nothing that says that all channels -must- be digital. Mixed mode is a real functional feature that might be a good solution. The ITU and other involved groups might decide to keep some channels analog. Or not. The standard hasn't been published yet.
But that sure hasn't stopped people from making those sweeping generalizations or wild claims. Dooming something like this to failure without knowing the technical details just shows a childish knee jerk reaction to something they don't have complete information on.
The nice thing is that the ITU won't be asking the amateur radio community, or the scanner community for their approval on this. The decision won't be left up to opinions, or how some digital radio set up a decade ago for a retail operation worked.
And thankfully the decision won't be based off the opinion of some "expert" with a CCR digital radio….
And claims of a $1,200.00 marine digital VHF radios? I can buy a brand new, modern <$400 NXDN/analog/mixed mode VHF radio with GPS installed as well as IP67 and FCC Part 80 certification right now, today. And those prices continue to drop….
Believe it or not, there are actual intelligent engineers and professionals at the ITU that will make decisions outside the realm of radioreference. They did just fine with GMDSS, EPRIBS and lots of other technology that provides better results than the old analog systems did.
cpetraglia
Member
I would disagree. I have been a scanner hobbyist for 45 years. I have owned everything from the cheapest receivers to a few BK professional radios.
I have listened to all the local systems in my area for many years through all the transitions. I have to say that with a proper setup, the current P25 digital systems sound 1000 times better than all the older analog systems used to.
Granted, one needs a decent antenna and a basic knowledge on setting up the receiver. But the results are superb. No noise, no static, just pure FM like voice. Not to mention the reems of data that goes along with the newer systems.
Sure, for me it was a learning curve. But once I figured it all out, it only makes sense.
nsrailfan6130
Member
I am sure it wouldn't be desireable, but, if a system is set up properly the chances of that happening would be far less than what it would if someone who was inexperienced set up the system. My biggest issue with analog is a lot of the white noise that comes in if you transmit from a certain distance plus the interference that comes with transmitting on say a ham radio, being a ham op you may get that from other repeaters close by to where you are (Which would be a good reason to set up a PL/DPL). But anyway, that being said, I am just stating a preference. no more no less.
ecps92
Member
Key words here = Properly set-up System.
USCG can set-up and design an awesome system. Now add your average weekend boater and the system goes to crap
USCG can set-up and design an awesome system. Now add your average weekend boater and the system goes to crap
mmckenna
I ♥ Ø
It should come as no surprise to anyone that the average recreational boater -today- has a pretty crappy analog radio setup. Most recreational boaters buy the cheapest VHF radio they can get, and then want a compact/low profile antenna, then get upset when it doesn't work correctly. Sort of like the posts we get on this site with sub-par CB, GMRS or ham antennas.
The saving grace is that the USCG VHF radio network was designed from the ground up to provide communications with 1 watt VHF handhelds working at 0 feet above sea level. They knew that average Joe boater out on the weekend is going to be running a crappy setup at best.
nsrailfan6130
Member
The same can be said for statewide public safety. But, that's for another thread. I am not disputing the fact that it can and probably will happen. I am still curious as to how it will all shake out in the future.
nsrailfan6130
Member
Maybe you know this, what kind of distance would a boater expect to get if any running a analog vhf antenna as you described?
mmckenna
I ♥ Ø
A "distance to horizon" calculator will tell you that with pretty good certainty. USCG usually has their stuff on coastal mountains or towers and has pretty good coverage.
nd5y
Member
USCG has VHF coverage maps on their web site.
nsrailfan6130
Member
Thanks for the information guys.
Not to mention the fact that the marine environment is quite harsh. Even if the boat had a good VHF set up when it was originally installed, it may not be in such good shape after a few years of exposure to a salty environment. And on boats many of the components are often in difficult places to access for maintenance, for example antennas on the masthead of sailboats.
I sold my sailboat years ago, but I still sometimes lurk on a sailing forum. There are frequent threads about the problems people have trying to repair, upgrade, or replace VHF and other marine electronics gear.
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Ubbe
Member
The main difference in digital radios are that the audio level are so much more critical. In analog radios it doesn't matter if you shout in the mic or just whisper, the human ear can adjust to those level differencies. In digital the processor needs the correct level or it will get distorted audio quality either due to over modulating or not modulating enough that will use too little resolution in the databits and will sound robotic.
In professional and commercial use the digital systems are mostly setup by experts but if private boat owners get digital radios they would for the most part fail miserable in audio quality. I hear many HAM's that have their modulation way off in analog transmissions and when they use digital radios they sound terrible, and they should be better at that than the average person.
/Ubbe
In professional and commercial use the digital systems are mostly setup by experts but if private boat owners get digital radios they would for the most part fail miserable in audio quality. I hear many HAM's that have their modulation way off in analog transmissions and when they use digital radios they sound terrible, and they should be better at that than the average person.
/Ubbe
mmckenna
I ♥ Ø
All the commercial digital radios I've set up have various capabilities for addressing this, including AGC on the transmit audio as well as received audio.
And it works pretty well. Most of the companies selling the higher end radios got hit pretty hard when they first came out due to this issue. Using a radio next to a pump panel on a fire truck would screw up the audio. But now they've pretty much solved that, and the solutions work quite well.
And that's the difference between marine radio and ham radios. A ham radio anyone can get in the controls and mess with it.
In the USA, doing that with a marine radio requires a specific GROL license.
The end users of the marine radios won't have access to the internal controls or programming. It'll be set up appropriately and locked down to keep people from messing with them.
I have to wonder how many (if any) people view the title of this thread and click on it and think about how this group might be changing their communications system (they are a band but still Marines that can probably augment the other Marines in support the defense of the capital).
Sorry, but
I've done this a couple of times.
(Yes, I know they already use digital).
Thanks
Joel
Sorry, but
I've done this a couple of times.(Yes, I know they already use digital).
Thanks
Joel
I spent a fair amount of time on analog conventional and a little bit of trunking (pre-digital) before leaving the business in the late 80s. In that world, it was mostly just about setting dev correctly on commercial off-the-shelf stuff. On ham stuff and/or adding remotes or linking, there was also feeding audio to/from the right place (pre/de-emphasis and other filtering, impedance, etc.). What kind of different stuff do you have to do with digital? Not knowing any better, one might think it's pretty much plug-and-play, like computer networking, where it either works or it doesn't.
Well you don't know what you are talking about and/or are dishonest.
Would you send music over an IMBE or AMBE codec?
You really think that sounds better than even AM broadcast?
These codecs clamp down on sounds they think are interference, but aren't.
I don't think people like you have a clue about bandwidths and the limits those bandwidths put on how much data can be passed.
Want to laugh at this?
