Im curious how "rigorous" that the 450 testing was done on AP's On Sun, Aug 27, 2017 at 2:23 PM, Steve Jones <[email protected]> wrote:
> I think when they did the 320 they had a boatloaf lots but that was > performance. > > Component testing is pretty rigorous, unit not so much. I like seeing time > lapse of that stuff, watching polymer bake the equivalent of 100 years in a > test chamber, or slowly sandblast away. > > On Aug 26, 2017 5:34 PM, "Kurt Fankhauser" <[email protected]> > wrote: > >> Whats the most AP's that Motorola ever tested at one time? >> >> On Sat, Aug 26, 2017 at 3:04 PM, Lewis Bergman <[email protected]> >> wrote: >> >>> Motorola, as most large manufacturers, do their own testing. IP ratings >>> are a pretty simple test procedure that most do by themselves. >>> >>> On Sat, Aug 26, 2017, 1:39 PM <[email protected]> wrote: >>> >>>> I dunno, the Motorola test room in their canopy lab had hundreds of >>>> radios in it. >>>> >>>> *From:* Kurt Fankhauser >>>> *Sent:* Saturday, August 26, 2017 12:31 PM >>>> *To:* [email protected] >>>> *Subject:* Re: [AFMUG] Manufacturer MTBF ratings and actual lifespan >>>> of product >>>> >>>> So does anyone actually think that a radio manufacturer took 100 radios >>>> off the shelf and tested them simultaneous to calculate out some average >>>> and derive at the number they state? I highly doubt that many radios were >>>> tested especially considering the cost of some of these radios!!! >>>> >>>> On Sat, Aug 26, 2017 at 2:03 PM, Forrest Christian (List Account) < >>>> [email protected]> wrote: >>>> >>>>> Need to correct my example: >>>>> >>>>> 10 devices fail in the first year. 10% per year. 50% would be at 5 >>>>> years. So the MTBF is 5 years. Adam's explanation is likely also >>>>> accurate. >>>>> >>>>> On Sat, Aug 26, 2017 at 12:01 PM, Forrest Christian (List Account) < >>>>> [email protected]> wrote: >>>>> >>>>>> My understanding is that MTBF is usually calculated by taking a >>>>>> certain sample size, then seeing how many fail over a certain amount of >>>>>> time. From this number you can then use statistics to determine how >>>>>> many >>>>>> years the rest will last. >>>>>> >>>>>> A simplified example would be if you take 100 devices, and 10 fail in >>>>>> the first year, then you assume that 5 would fail per year, and the mtbf >>>>>> would be 5 years. >>>>>> >>>>>> Remember 'M' is mean. Or average. Which roughly means that only >>>>>> half of the units will still be working in that amount of time. It >>>>>> doesn't >>>>>> mean your particular radio will last that long, just that half of the >>>>>> radios will last that long. Yours might fail in 10 days or a year or >>>>>> never.... >>>>>> >>>>>> Personally, I believe that this method is rather dubious since some >>>>>> electronic parts exhibit wear-out. Electrolytic capacitors as an >>>>>> example. Even if very few devices fail at 5 years, there is a good >>>>>> chance >>>>>> that most will fail at 20 years after the electrolytic caps have dried >>>>>> out. >>>>>> >>>>>> On Sat, Aug 26, 2017 at 9:29 AM, Kurt Fankhauser < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Where do these MTBF ratings come from by radio manufacturers? Are >>>>>>> they just made up numbers the manufacturer "hopes" that the product can >>>>>>> achieve or is actual testing done to get to these numbers? I thought i >>>>>>> seen >>>>>>> a radio once with a 90 year MTBF rating. How they hell can they >>>>>>> determine >>>>>>> that? The components in the radio didn't even exist 90 years ago. >>>>>>> >>>>>>> If a radio manufacture states in the spec sheets that the radio has >>>>>>> a 40 year MTBF rating but then also admits that after 4 years expect to >>>>>>> have problems due to a design flaw, what does that mean? Is the expected >>>>>>> MTBF rating only good in a "lab environment" under "ideal conditions"? >>>>>>> >>>>>>> Seems to me the MTBF is just marketing fluff and actually doesn't >>>>>>> mean crap.... >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>>>> [email protected] | http://www.packetflux.com >>>>>> <http://www.linkedin.com/in/fwchristian> >>>>>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>>> [email protected] | http://www.packetflux.com >>>>> <http://www.linkedin.com/in/fwchristian> >>>>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>>>> >>>>> >>>> >>> >>
