cnynrat
Expedition Leader
"Mass of misinformation? Really? Sorry, I don't see much at all in the way of misinformation about PLBs over in the other thread: care to elaborate?
For Mashurst....406mhz PLB's....big Wiki.
- Thread starter xtatik
- Start date
"Mass of misinformation? Really? Sorry, I don't see much at all in the way of misinformation about PLBs over in the other thread: care to elaborate?
xtatik
Explorer
Sure, as soon as you kick down the hard numbers that demonstrate the differences in reliablilty between PLB's and HF radios. I also would like to see how these incidence levels could be expected to correlate to an actual moment of need. Until then, no. I can demonstrate my claims, you cannot.
This was one of the absurd spectres you contributed that helped in taking that discussion down a $h1?hole. Others politely attempted to point this out to you, yet you persisted. Are you still wanting to go there?
cnynrat
Expedition Leader
I asked a simple question: Where is the "mass of misinformation about PLBs" on the other thread. Frankly, I don't think your snarky comment is an appropriate reply.
If there is a "mass of misinformation" there, it should be corrected, or at least pointed out so newbies aren't lead astray. I happen to think there is very little, if any, misinformation about PLBs on the other thread, which perhaps is borne out by your inability to actually identify any.
Your obsession with this red herring question of identifying the probability of failure of your HF rig at some arbitrary time is wearing old. The question is not relevant to anyone's consideration of the tradeoffs between relying on an HF radio vs. a PLB for emergency communications. It is enough to know that the PLB will exhibit higher reliability due to their lower parts count and lower power dissipation which leads to lower operating temperatures. This will lead directly to the unavoidable conclusion that the PLB has a lower probability of failure at any time in its lifetime compared to an HF rig. This is elementary electronics reliability analysis. Whether it's a meaningful difference is an individual decision that should be dependent on a number of considerations. I've never said that HF rigs are so failure prone that nobody should consider them for emergency communications. In general, they are very reliable, but certainly not 100% reliable, which you may recall is the statement you made that lead to the other thread unraveling. We were doing fine for the 6 pages before then.
cnynrat
Expedition Leader
xtatik
Explorer
Actually, the less than 100% reliablility point was your red herring. I'm certain anyone reading my original post would assume that I'd have a serviceable radio. It's a well reasoned assumption. It's interesting that the electronic reliability of either type of unit hadn't been brought up to that point.
What I'd like to do is clear the air for anyone that might read this and now have doubts about the reliability of either type of unit. If you're tiring of, or are incapable of calculating the differences in reliability between the units... let's try this instead.
Here are the three defining questions someone might have after reading these two threads:
Given the same scenario.......
Is there ANY PRACTICAL REASON that I couldn't rely on the electronic workings of my HF radio at a particular time of need?
Is there ANY PRACTICAL REASON that I couldn't rely on the electronic workings my PLB at a particular time of need?
If the answer to each question is no (a reasonable assumption), in a discussion regarding the benefits and shortcomings of each device, is there ANY PRACTICAL REASON to subject the discussion to injections of doubt regarding electronic circuit reliability in one or the other?
Not true. Here's a very rudimentary example....protection circuits. Protection circuits are just one example where more components lend more reliability. There are many other examples, but this one is easy to understand. They can be comprised from any number and type of components depending on the circuit. I've installed HV glitch resistors on power supplies, placed diodes in meter protection circuits and added gobs of resistors to filter cap bleed banks....all in efforts to ensure reliability. They work, and adding components in many circuits will EXPONENTIALLY increase the overall reliability of these circuits and electronic devices. In many cases, it's the simple circuits that have no protections or redundancies that suffer the most.
No doubt, heat is the enemy in electronics and I've had that discussion with others here in the past. Heat issues can be mitigated in many ways. In fact, more components can even lessen the accumulated heat in a given space/device....and I'm not talking about adding a fan, although it should be mentioned. Component ratings, component spacing (in all directions...stand-offs), chassis design (sinking), and ventilation are just some of the other considerations.
Basically, these units are built to the same standards using the same methods. Usually components are surface and/or through mounted to boards using either wave or reflow soldering methods ..usually the latter.
http://en.wikipedia.org/wiki/Wave_soldering
http://en.wikipedia.org/wiki/Reflow_soldering
In all likelihood, it's done with the same brand of machinery.
http://www.ersa.com/reflow-soldering-en.html
And, it's all done to commercial spec with commercial grade components (same as MilSpec since 1994, COTS).
In the world of electronics...all things are melding into one...and this has been happening for at least two decades. The inefficiencies presented by having differing grade components and assembly methods are being done away with. Actually, it's been going on in electronics for even longer. I've got NOS JAN (Joint Army Navy) 6L6WGC tubes mfr'd by Phillips that were used in 50's and early 60's era military cockpits. I use them in the guitar amps I've built. But, these "MilSpec" tubes were no different than the ones my Dad was putting in our TV set back then. I'm sure Phillips billed the Navy at a higher price than what my dad paid.
http://en.wikipedia.org/wiki/Commercial_off-the-shelf
http://www.militaryaerospace.com/ar.../plastic-ics-get-hot-in-high-temp-market.html
http://www2.l-3com.com/tw/index.htm Search "COTS" or "COTS Initiative" on this site. This is one of the largest military electronics systems contractors.
Yes, I recall and no you weren't doing that well. I can flip to that thread and still read my justification for that statement. My point was that I could reasonably expect my radio to work as well as my PLB in a time of need. I think most who read my post would be assuming the same. Again, I own both, but if my radio is working....I'll say it again...I am 100% assured that I could not only make contact, but could also pass vital information and initiate a rescue mobilization. Until that point, a PLB zealot was having his way with the thread and was wanting to summarily dismiss of any hams by accusing them of having a bias (pot meet kettle).
PLB's are a very worthy addition to the kit, but are more limited in overall utility (to the overlander...er, whatever). They are a last ditch device to be used only in circumstances where there is risk of great physical harm or death and when other communication means have been attempted/exhausted.
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