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> >>> >>> >> >
