[Elecraft] K3 power loss: Last settings forgotten

[Ralph Tyrrell]

Ron:
I have never had this problem. I often operate with the power supply off.
I do have 75 AH of batteries connected to the K3. I sometimes operate for 3 to 5 days (intermittently) before turning on the power supply. Just my backup plan.
 
73, Ty, W1TF, K3 #696


--- On Sun, 3/1/09, Ron D'Eau Claire <ron at cobi.biz> wrote:

> From: Ron D'Eau Claire <ron at cobi.biz>
> Subject: Re: [Elecraft] K3 power loss: Last settings forgotten
> To: "'Erik N Basilier'" <ebasilier at cox.net>, elecraft at mailman.qth.net
> Date: Sunday, March 1, 2009, 1:57 PM
> Interesting Eric. 
> 
> That's one you might post to K3support at 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:ebasilier at cox.net] 
> Sent: Sunday, March 01, 2009 10:44 AM
> To: Ron D'Eau Claire; elecraft at 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" <ron at cobi.biz>
> To: <elecraft at 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