Totally agree. I was somewhat appreciative that FD helped me find the problem as soon as possible and was wondering if solid type TX would be a good way to do an accelerated test. From what I'm hearing now and I agree a FD simulation w/ full QSK running is probably more real world.
You are correct in that all I really want to do is find any underlying problems quickly so that I can be assured that I'm out of the 0.1%. >From reading the list I know that the K3 is a brute and they just flat out don't die! I just wanna make sure that after getting one that did that I've chased out all the demons... :) ~Brett On Fri, 2008-07-04 at 10:08 -0400, Don Wilhelm wrote: > Folks, > > John was quite correct to term his test an 'Endurance Test'. I have > worked as an Assurrance Engineer for the latter part of my career and > would like to offer the following: > > The purpose of any 'burn-in' tests for complete electronic assemblies I > have encountered is *not* to stress the DUT to its limits, but simply to > catch any early life failures that may be lurking. Burn-in testing of > individual devices is different than any burn-in of a complete > assembly. Simply running the assembly continuously under normal > conditions for a period of time is normally sufficient. > > Early life failures can and do occur, but they are not common. > > If one would want to do a 'burn-in' for the K3, I would advocate that > alternate receive and transmit cycles be done over a period of a > several days (half max power level should be sufficient) or so (you get > to pick the time frame that *you* define as 'early life'). > > Other than catching early life failures, a burn-in period for electronic > packages such as the K3 serve no purpose at all. The continuous > operation just makes a lurking early failure happen sooner than it would > normally. If you are expecting anything more from such a test, it just > "ain't gonna happen". > > Of course, one can always just operate it as normal for the first 30 to > 90 days and regard any failure that occurs as an early life failure - > that works just as well as continuous operation. > > We did hear of one K3 that failed during Field Day, but there are over > 1000 K3s out there, and an early life failure rate of less than 0.1% is > very good, even though it is quite disconcerting to find oneself in that > small percentage region. > > 73, > Don W3FPR > > John King wrote: > > Disclaimer - the following test method is not approved or > > sanctioned by Elecraft. Conduct any testing at your own risk. > > > > I work in Quality Assurance in my day job (30 years and counting.) > > > > Long before FD I performed a 24 hour endurance test on my K3 > > to approximate worst-case FD conditions. I recorded a CQ FD message > > similar to the actual message we would be using at FD into one of > > the K3's message memories, then set the message repeat time to > > minimum. The K3's output power was set to 120 Watts and the rig > > was connected to a 50 ohm dummy load with a Bird thruline wattmeter > > in line. The DC input voltage was set to 13.5 volts. The test was > > performed at ambient room temp, about 24 degrees C. The K3 sent > > the continuous message loop for a 24 hour period without incident. > > > > The actual environmental conditions at our FD were a bit more > > severe than the test conditions above. The K3 was operated in a > > 4-man dome tent exposed to full sun with an outside air temp > > approaching 90 degrees. We didn't measure the actual temperature > > inside the tent, but my informal assessment was "hot as hell." > > Of course, the transmit duty cycle in actual FD use was less > > demanding than the test duty cycle. I had high confidence that > > the K3 would be up to the task, and it was. > > > > I'm sorry to hear about your failure at FD. I have heard no other > > reports of FD failures, and to my knowledge the VP6DX crew had > > no failures during their operation earlier this year. It may be > > of small comfort to you, but I regard your failure as an anomaly > > - stuff happens. Overall, the K3 is establishing a reputation as > > a very reliable field rig. > > > > > > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
