[Elecraft] K3 power loss: Last settings forgotten

[Erik N Basilier]

Ron, in those two instances where I had to take some extra steps to make
the K3 work normally again, I did correspond with Gary at Elecraft, but no
conclusion about cause was arrived at. It was only our conversation today
that made me think of the remote possibility of a connection between those
incidents and my power shutdown habits. And because you suggested it,
I now think that I should write Elecraft again about it. Thanks.

Erik K7TV

----- Original Message ----- 
From: "Ron D'Eau Claire" <ron at cobi.biz>
To: "'Erik N Basilier'" <ebasilier at cox.net>; <elecraft at mailman.qth.net>
Sent: Sunday, March 01, 2009 11:57 AM
Subject: RE: [Elecraft] K3 power loss: Last settings forgotten


> 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
>>
>
>
>