Communication options

[Mashurst]

Come on Kids. Can't we try and keep it productive.
I really would like to see a thread about 406 PLBs. In this thread its off topic but I still have questions about the PLBs that have not been addressed here. I would start it but this week has been very busy what with the world wide zealots on the air event this weekend and a technician class to run all in addition to my normal family and work responsibility. I will do it next week if one of you folks that have used or at least own a PLB don't beat me to it.

 

[Karma]

HI Mashurst,
Based on the input in this thread, almost no one here owns a PLB which I find totally incomprehensible. I do, but how many others? It's probably too late for a poll but I would be curious.

Sparky

 

[Mashurst]

I'm basically begging you to start a new thread. This one will soon be buried in obscurity. If you start a new one about them there is a good chance we can get it a sticky. I had never heard of these till this thread as least for land use. I want to know more about them but this thread is kind of out of hand. This thread, lest we forget, is supposed to be about a breakdown within cell range...

 

[DreamingOfExpeditions]

Typical engineering discussion, spiraling away in technical details while the original question fades into obscurity.

" you got two halves of coconuts and your banging them together!"

"maybe a swallow grabbed it by the husk..."

"Maybe, but African swallows are not migratory"

Here's the answer, given a cell, HAM and a sat backup (spot or EPIRB), the meantime to failure of the operator will be far before all of these systems fail simultaneously.

 

[xtatik]

This is really a rather silly line of argument, as I suspect you are well aware being a super-duper HF ham zea ... err enthusiast.

MTBF, that's MEAN Time Between Failures. It's about probabilities, not events that happen at some time certain in the future. Let's assume you were to buy a brand spanking new HF rig tomorrow, and a brand spanking new PLB as well. You go about your travels, using the radio to contact folks in Argentina from time to time or whatever it is that you HF guys do, and tuck the PLB away in your emergency bag for, well, emergencies. At any time in the future, whether that be next month, or five years from now, the probability that your HF rig fails will be higher than the probability that the PLB fails. Why? The HF rig has more components that are operating at a higher average temperatures since it's pumping out, I'm guessing, 100W, and it's also accumulating operating hours at a faster rate than the PLB.

That doesn't mean don't rely on an HF rig - as with most modern electronics the reliability is quite remarkable. I think your proposed suite of comms gear (HF + Iridium satphone) provides very robust emergency capabilities, albeit at a higher than average price. I just don't think you can claim 100% probability of successfully calling in a SAR team while implying that the probability with a PLB would be less. Just on the question of the failure rate of the electronics I think the PLB has an advantage.

Dave
I think you may be missing what I'm saying. I fully understand the concepts behind MTBF and if you back up and read through my points on this, you'll note that I've (more for sake of discussion) conceded that the never or seldom-used PLB might have a barely registerable advantage in electronic component reliability due to it being used less.
What I'm pointing to is that it would be almost absurd to suggest that the planets would misalign in my moment of need and cause a circuit failure in my radio. I just don't see a reasonably measurable and mention-worthy probability.

 

[xtatik]

Here's the answer, given a cell, HAM and a sat backup (spot or EPIRB), the meantime to failure of the operator will be far before all of these systems fail simultaneously.

Thank You! So true.

 

[xtatik]

HI All,
You should not assume that I have no experience with ham radio or expertise. First, I have worked in communication electronics for over 50 years, longer than most of you have been alive. I worked for many years for NASA on the Mercury, Gemini and Apollo programs designing high performance PCM telemetry data communication systems to be used by orbiting space craft. Then I left NASA and worked for Los Alamos National Laboratory for nearly 30 years developing high performance digital data acquisition systems that operated in highly radioactive environments.

I have been around ham radio a great deal. Many of my co-workers and friends are hams and we have spent hours discussing the technical aspects of ham radio such as the advantages of single side band, modulation techniques, antenna theory, wave propagation through the atmosphere, and most interesting to me, filter theory. All very interesting stuff. I have also studied the history of amateur radio as well as radio theory in general. Oh yes, many hours in stuffy ham shacks, most of them very enjoyable.

I have studied for a ham license when code was still a part of the process. I never went so far as to get a license because of life intruding and the fact that I found that most ham contacts were deadly boring. It just didn't capture my interest on a practical level though theoretically, radio is very interesting to me. Of course, now you guy's are mere operators because everything can be bought off the shelf. When I was most involved, much of the hardware had to be designed by the ham. Therefore, most were electronic engineers as am I. You all have really just turned into sophisticated button pushers with a large wallet to buy what you want. How many of you could actually design a ham radio? I can.

I have owned ham transceivers and have monitored the ham bands quite a bit. That's how I discovered that ham radio was not going to be one of my avocations.

I have tremendous respect for ham operators and the development of ham radio as well as the advances ham radio has made to radio in general. The best of the ham operators are good indeed. But not all hams are created equal.

I know it is comfortable for you to think I disagree with you because I don't know what I am talking about. It's just not true. My attitudes about emergency rescue is strictly based upon my evaluation of available technology and which of these has the best chance of succeeding, without fail. This is not unlike doing the system reliability analysis of a space telemetry system. All factors, including electronic, mechanical, environmental, and human must be taken into consideration in the space environment where a failure is not an option.

Some of you have revealed your prejudices about PLB. You seem to feel that it a dumb technology, that it doesn't challenge your technical expertise. I'm sure this is true. But this doesn't make the PLB system less effective. It just removes your personal skill set from the discussion and replaces it with a system that is nearly 100% effective. You consider this to be a drawback of the PLB system. I consider it to be its primary strength. Keep your ham fingers out of the pie. The system will be better statistically.

Sparky

Sparky
I'm astonished you could have this exposure and arrived at your conclusions. I'm sorry, but I think something in the experience went missing.
First things first you are taking liberties with some of the things that have debated in this thread. I don't think anyone has stated that the PLB technologies "are dumb". They are not. But they are also no more sophisticated and in some case are less sophisiticated than systems available to hams. This is a fact. Hams have their own satellites to play with and communicate through if they choose to. They have many other extremely reliable digital forms of communication that can reach around the planet with minimal power and during the worst of propogation.
Secondly I've been soldering circuits since 1969, and was first licensed in 1974. I built my first radio that year, a Heathkit HW-16. It was a pure CW machine as that was all my Novice class license would allow. I didn't upgrade to General class within a year as was mandated back then. Instead I discovered girls, guitars, surfboards and weed. But, I continued to mess with guitar amps and have built a few. My Dad who has been involved in amateur radio for as long as I can remember enjoys the use of a Heathkit SB200....one of two that I completely re-capped and rebuilt last year.
Oh, and BTW, I do own a compact PLB. However, it doesn't ride in my truck. It's got other intended and better suited purposes for me.

 

[cnynrat]

Dave
I think you may be missing what I'm saying. <snip>

No, not really, I completely understand.

I do think you are proving Sparky's point about ham radio zealotry though.

 

[cnynrat]

I'm basically begging you to start a new thread. This one will soon be buried in obscurity. If you start a new one about them there is a good chance we can get it a sticky. I had never heard of these till this thread as least for land use. I want to know more about them but this thread is kind of out of hand. This thread, lest we forget, is supposed to be about a breakdown within cell range...

I think that's a good suggestion, and I will undertake to put together some background information on distress signaling devices. Be patient please

 

[xtatik]

No, not really, I completely understand.

I do think you are proving Sparky's point about ham radio zealotry though.

You don't understand. Your attempt at comparing the probabilties for failure at a precise point in time are absurd. You can attempt to calculate the reliability of differing communication devices, but you can't reconcile or correlate their failures to a precise point in time....or an emergency event.
The likelihood of failure occurring at a precise time of need is incalculable. This isn't zealotry...it's reason, and I'm sorry I had to take on this issue with you.

 

[cnynrat]

You don't understand. Your attempt at comparing the probabilties for failure at a precise point in time are absurd. You can attempt to calculate the reliability of differing communication devices, but you can't reconcile or correlate their failures to a precise point in time....or an emergency event.
The likelihood of failure occurring at a precise time of need is incalculable. This isn't zealotry...it's reason, and I'm sorry I had to take on this issue with you.

You are the one trying to compare probabilities for failure at a precise point in time, not me. That question which you keep asking isn't even the relevant question. There is no need to calculate the probability of failure at a precise point in time. It is sufficient for the purposes of this discussion to know that HF radios do fail from time to time, and that the probability of failure of an HF radio is higher at any given time compared to the probability of failure of the simpler and lower power PLB.

You came on and made this statement:

A HF radio can summon help 100% of the time from anywhere on this continent.

That statement is patently absurd, and I'm sorry I had to call you on it. Aside from the fact that HF radios do in fact have finite MTBFs and are therefore subject to failure, there are any number of other reasons, all quite reasonable scenarios, by which you could fail to summon help with an HF radio.

 

[ratkin]

Come try some radios . . .

Thanks for chiming in Bob. This thread has confused me more than anything. I think the next outing I may just hang out and ask you questions. And I was wondering about all this SAR stuff. Maybe that happens out west since all the remarks about SAR were from people on that side, but it doesn't happen here. In Lumpkin County we had a backpack on the ambulance and would have to walk the AT if there was a call there. Hopefully you didn't get the 300lb guy on the truck that day. The wilderness calls out here always went to the local authorites. *Maybe*, just maybe, someone might contact the Ranger Camp to see if they could assist but that would be it.

Jeff,
If you're out and about this weekend, for a full 24 hours from 2:00 PM Saturday to 2:00 PM Sunday, there will be folks out practicing using their radios outdoors on emergency power. All of these groups encourage folks to stop by and try things out or just ask questions. Kids really have fun, once they get over being nervous talking into a microphone. You can check this website to find one closest to where you'll be. If you happen to be down kicking around 4 Wheel Parts in Norcross, I'll be at this location with my kids until around 5-5:30 PM Saturday. This one is a joint set-up between a club and Gwinnett ARES, which is probably the type of ham radio operation that you would be most interested in.

Hope this helps!

- Richard

 

[DreamingOfExpeditions]

Sorry dude, you clearly don't understand MTBF, or probability.

I'm afraid that the MTBF argument is tenuous at best. Most devices are measured in years, and given use and set up the REALITY is that they have 100% up time. You can always find an outlier, but you did say MEAN.

If I have my rig and put a HF rig with a meantime to failure of 10 years, chances are I'll replace the rig within that failure band, and so many good engineers like yourself designed that into the unit. Marketing and sales know exactly what the turnover of these units are and can engineer a product accordingly. Reality is its the heat sync we are talking about. It's always about heat. A quick search of the used market shows any number of units available in the 5 year old range. So that's insight into that failure rate. The PLB data I saw has a recommended replacement of 10 years (the makers recommendation) so that'll tell you what they think it is.

Calculating is easy. Engineers always have big calculators and fancy equations. But what does it matter if I tell you your 5 times my likely to get cancer with exposure to x material when the reality is 5 x .0000001 is still next to nothing.

I'd love to see your real data even on an analogous device. I know statistics quite well and think that would prove or disprove your point rather clearly.

 

[cnynrat]

I'm afraid that the MTBF argument is tenuous at best. Most devices are measured in years, and given use and set up the REALITY is that they have 100% up time. You can always find an outlier, but you did say MEAN.

No device built by man has 100% up time. None. Not in theory, or in reality.

Do modern electronics have very good reliability performance? Yes, in general they do. However, there are exceptions. Just to use one example, peruse the reviews of certain ICOM models on eham.com and it's not difficult to find people with complaints of early failures. Someone might say, well I don't own an ICOM model XYZ, but the problem is you sometimes don't find out about these product weaknesses until after you've made your purchase.

We characterize failure probabilities in terms of Mean Time Between Failures. Failures will typically occur in an approximately normal distribution about the mean. So, as a first order approximation a device with a lower MTBF has a higher probability of failure at any time during it's lifetime compared to a device with a lower MTBF.

I don't think I've suggested that anyone should stay away from HF ham radio as an emergency communications tool. You are correct that the reliability of most of these products is quite good, and shouldn't be a concern. I simply think it's incorrect to assert that any emergency communication tool has a 100% probability of success. There are way too many variables that can get in the way of that, only one of which is the failure of the electronics itself.

I also agree we're talking about a very fine point here. The difference between 100% and 99.99% may seem small, but among other things, the acceptance of that reality might lead one to take steps to be better prepared to deal with any emergencies on a self sufficient basis rather than assuming that they are absolutely guaranteed to be able to call for help.

 

[taugust]

Keep in mind again, I have worked for years for this agency, I have the OK from Chief to access the channels they operate on if I happen upon an accident again, and I have the skills to help. If I accessed the channels for emergency traffic from an accident whould the FCC come after my license or would the Chief have to make a complaint? The last wreck I was on I started two helicopters and flew them out...and the on-duty guys were happy I made the decision and had them en-route. And this is something that may never even happen again, I am just wanting to confirm before I get one. I have already decided to get an InReach device too for anything other than life or death.

In this one county I have pulled a guy from a burning car...getting burned myself, made the decision to fly six different people out and followed through with it, accessed one patient via a rope system, and tended to about 10 critical patients from motorcycle accidents, all in about six years and OFF DUTY. I know these guys and they jokingly tell me to stay off the road because I am an obvious **** magnet. If I have a peice of equipment that can relay vital information to people that can make a difference I would think its the right thing to do. Are you saying if I did the FCC would pull a license?

Jeff,

From the reading I have done, if you contacted your own agency, the FCC probably would never know about it. If you contacted, say, the sheriff dept., they would not know who you are, and may register a complaint with the FCC. While the rules state that you can make an emergency call using any means available, licensed or not, you could still be subject to losing your license after the fact if some bureaucrat decides you should. In order to do what you want to do, you would have to modify the radio, and they could get you for that.

My suggestion would be to check out one of your agency handheld radios when going out, and making the call on that. Or get a surplus public service radio and mount in you vehicle. Then you would be completely legal, ham radio or not.

For the record, I am a ham radio enthusiast as well. I have made an emergency call when cell service was not available. I wrote about that incident here: http://www.expeditionportal.com/forum/threads/14325-Amateur-Radio-in-an-Emergency?