K3 and KPA500 aux power on difference?

[tomb18]

Hi,
I am about to enable remote on/off on my K3 and I just noticed in the manual for the KPA500 that the power ON line must be pulsed to ground and not left low.  This is different than what the manual says for the K3 where you are supposed to pull the line to ground until you wish to power off.
Why the difference?
Any ways irrespective of the reasons, the what is the situation with the Elecraft AUX cable to connect the K3 to the KPA500?  I guess that the power on/off lines are not connected right?  What this would mean is that one would need two of the Y cables, one at the K3 and another at the amp, right?
Assuming that this can be worked out,, how would one turn the amp out of standby? Can this be done by the K3?
Thanks for any insight into this.

Tom
VA2FSQ

[Iain MacDonnell - N6ML-2]

Hi Tom,

The K3 manual is misleading on this. In fact, you do not need to keep
the "POWER ON" line pulled to ground during operation. I wrote myself
a little Java program to power on my K3 remotely. It toggles the DTR
line on a COM port on for 500ms, then off again. That DTR line pulls
the "POWER ON" pin to ground with a transistor, and the K3 powers on
(and stays on). Other lines in are used for PTT and FSK, so I have to
close the port if I want to do RTTY! To power off (later), I send a
"PS0;" command from my rig control software. I don't know why the K3
manual is written the way it is - it just seems wrong.

The KPA500 is a bit different. So long as the power switch on the back
is on, the processor is active, and can be instructed to power on (and
off) everything else via commands. I'm currently using the KPA Utility
to do this (through another COM port). If you're going to be operating
your KPA500 remotely, having the KPA Utility running may be a good
idea anyway, so perhaps you can use this method too.

(AFAIK) there's no way to have the KPA500 power on/off with the K3
automatically.

73,

    ~iain / N6ML



On Wed, Dec 14, 2011 at 4:51 PM, tomb18 <[hidden email]> wrote:

> Hi,
> I am about to enable remote on/off on my K3 and I just noticed in the manual
> for the KPA500 that the power ON line must be pulsed to ground and not left
> low.  This is different than what the manual says for the K3 where you are
> supposed to pull the line to ground until you wish to power off.
> Why the difference?
> Any ways irrespective of the reasons, the what is the situation with the
> Elecraft AUX cable to connect the K3 to the KPA500?  I guess that the power
> on/off lines are not connected right?  What this would mean is that one
> would need two of the Y cables, one at the K3 and another at the amp, right?
> Assuming that this can be worked out,, how would one turn the amp out of
> standby? Can this be done by the K3?
> Thanks for any insight into this.
>
> Tom
> VA2FSQ
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-and-KPA500-aux-power-on-difference-tp7095755p7095755.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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