[Elecraft] K2 Remote DC Power Control

[Don Wilhelm]

Tom,

First the answer about the K3 - there is some "cleanup" work that must 
be done when the K3 is powered off, so the power off button should be 
used rather than just "pulling the plug".  With the K2, there is no 
difference between "pulling the plug" and using the power switch.  Yes, 
just like your computer, the K3 is exposed to writing bad data if the 
plug is pulled (or a power outage occurs).  The chances of anything 
really disastrous is small, but some "strange happenings" may reveal 
themselves after such an event - the real answer is "it all depends" on 
what the K3 was doing at the time power went out - if it was writing 
something to storage, that "last used frequency, mode, etc." may not be 
preserved properly.

If the base K2 and the KPA100 are mounted in the same box, then the 
situation is different - you would have to interrupt the higher current 
connection (to the KPA100) if everything were connected normally.
Now, there "is a way" -- if you do not connect the AUX 12V connector 
from the KPA100 to the base K2,  the base K2 will not be powered by the 
KPA100 power supply connection - you will have to power the base K2 from 
the coaxial connector.  That makes the power off conditions the same as 
with the remotely mounted KPA100.

73,
Don W3FPR

On 1/15/2012 8:26 PM, KG3VTomZ at gmail.com wrote:
> Don,
>
> Thanks for the reply, and for all your other help in configuring my K2 
> station over the last 5 years.
>
> Just out of curiosity - can this not be done if they are mounted in 
> the same box? I think when mine were configured that way, there still 
> were two separate 12V inputs - or do they get tied together? I would 
> like to know if my timeout-switch approach would be useable by someone 
> with the KPA-100 in the same chassis as the K2-base.
>
> Interesting that it sound like it is not as "safe" to pull power from 
> the K3 during operation. What about a natural power outage event? 
> Would there be some complications in the recovery process?
>
> 73, Tom
> KG3V
>
>
> On , Don Wilhelm <w3fpr at embarqmail.com> wrote:
> > Tom,
> >
> >
> >
> > Yes, it is sufficient to kill the power to the base K2 (when the 
> KPA100 is mounted remotely).  Unlike the K3, there is little to be 
> lost (bits mixed up) if you turn the power source off for the K2 
> during normal operation.
> >
> >
> >
> > 73,
> >
> > Don W3FPR
> >
> >
> >
> > On 1/15/2012 2:14 PM, KG3VTomZ at gmail.com wrote:
> >
> >
> > I am assembling a remotely-operated K2 station. I need a timer that will
> >
> > kill a "runaway transmitter." I am planning to install a kill-switch 
> on the
> >
> > 12 volt DC supply, as that is the only way I can be sure to disable the
> >
> > transmitter. If I have a K2 and the separate 100W power amp, is it
> >
> > sufficient/safe to just disable the power to the K2 base unit (leaving
> >
> > power to the amp connected)?
> >
> >
> >
> > Anybody else experienced in auto-shutoff of a K2?
> >
> >
> >
> >
> >
> >
> >