Interesting Eric. That's one you might post to k3supp...@elecraft.com. I've not seen it here and I suspect Wayne would be surprised to see it. (He monitors that list carefully.)
Even though I frequently hit the POWER button switching off the main supply, when working on the K3 on the bench testing assembly procedures, etc., I often just "pull the plug" with the K3 live with no ill effects. Indeed, the one problem with shutting down the K3 that I've seen was that if the power supply wasn't turned off, a few K3s wouldn't turn on again later! That was traced to small current leakage through the KPA3 that managed to keep the CPU partially "alive" so it never did a complete shutdown. But that's just the opposite. Turning off the main supply "fixed" the problem (it's also fixed by the addition of a 1N4148 diode as described in http://www.elecraft.com/K3/mods/KPA3_12V_Sense_Modification_Rev_A.pdf) Ron AC7AC -----Original Message----- From: Erik N Basilier [mailto:ebasil...@cox.net] Sent: Sunday, March 01, 2009 10:44 AM To: Ron D'Eau Claire; elecraft@mailman.qth.net Subject: Re: [Elecraft] K3 power loss: Last settings forgotten Ron, I have been shutting down the external power rather than using the K3's power switch hundreds of times, a habit I established with earlier radios. I am comforted to know that you have also shut down your K3 in a similar way with no ill effects. But one thing now comes to mind that I didn't think about previously. Twice in several months of having the K3 I had a problem where the radio seemed disconnected from the antenna and showed a high swr on transmit. I jiggled the connector pins at the automatic tuner board etc. to no effect. At the first instance, the radio just started working normally after I used its power switch to power down and back on again. The second time (months later) I had to reload the firmware to get back to normal. Of course, there is nothing to say that either incident had anything to do with how the radio was shut down, just something that came to mind. If there were a chance of corrupting the firmware by unexpected power loss, then it would have implications for portable operation where alligator clips happily jump off of battery terminal posts etc. 73, Erik K7TV ----- Original Message ----- From: "Ron D'Eau Claire" <r...@cobi.biz> To: <elecraft@mailman.qth.net> Sent: Sunday, March 01, 2009 11:04 AM Subject: Re: [Elecraft] K3 power loss: Last settings forgotten > And the K3 is pretty resistant to the sort of craziness some CPU's > experience with unexpected shutdowns. > > I'm not aware of anyone who has had a "crash" of the system due to the > power > being pulled unexpectedly. I've done it hundreds of times working with my > k3 > without any ill effects other than, as you noted, some front panel control > settings may not be stored. > > FWIW that's true of the K2 as well. > > 73, > > Ron AC7AC > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
