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> >> >> >
