K3/P3 communication

[Bill Schwantes]

About 30 days ago I noticed that the K3 randomly keyed up and briefly
transmitted full power CW every few seconds while listening. This happened
with no action from me. I unplugged the paddle, mic, and headphones.  None
of these had any effect on this behavior. Tuning the K3 made this
uncommanded keying speed up and occur at a rate porportional to the tuning
rate.  This problem occurred abruptly.  The station had been working fine
for months before this occurred.

This behaviour stopped when I powered down the P3.

In the days following I went through the K3 menus, certain that I had
unintentionally selected something that cause this behaviour.  I found that
my transmit power setting for transverters was set below 1 miliwatt;
sometimes as low as  0.1 milliwatt. When I restored the XV drive power
setting to zero dB the uncommanded keying stopped, even with the P3 powered
up. Hmmmmm........

Now there's a different problem:  The P3 does not  initially display the K3
frequency upon K3/P3 power up.  Instead it shows the "#" symbol in the top
center of the screen. When this happens the P3 does not display the green
or purple frequency bands of the "a" and "b" VFO on the scope.  The
spectral display seems to be unaffected.  This condition can sometimes be
"fixed" by changing bands, especially when changing to a band that requires
an XV transverter to be powered up, but not always.  Band change
communication with the KPA500 occurs normally with or without the P3
powered up. Usually this P3 display behavior goes away and the P3 behaves
normally after 30 minutes of operation.  I seldom see it after an hour of
operation.

The station is all single point grounded.  Both the K3 and KPA500  are tied
to this single point ground.  P3 and transverters are not seperately
grounded.

The K3 has firmware revision 4.42. The P3 has firmware revision 1.09.

Apparently there is some marginal communication issue between K3 and P3.
has anyone observed this odd behaviour?

73, Bill
W7QQ
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[Alan Bloom]

Hi Bill,

> About 30 days ago I noticed that the K3 randomly keyed up and briefly
> transmitted full power CW every few seconds while listening.

Do you have anything connected to the "PC" RS-232 port of the P3?  This
sounds like it could be some software on the PC acting on the K3 through
the RS-232, either via the DTR or RTS lines (if they are set up for CW
keying in the K3) or some RS-232 command.  I don't think there is
anything the P3 could be doing to cause this.

> The P3 does not  initially display the K3
> frequency upon K3/P3 power up.

That could also be something connected to the PC port acting up or it
could be an RS-232 communications problem between the P3 and the K3.
Check that the lock screws are right on both ends of the serial cable
between the P3 and K3.  It could also be a bad cable or a bad KIO3 board
in the K3.  

Alan N1AL


On Wed, 2011-12-28 at 21:40 -0700, Bill Schwantes wrote:

> About 30 days ago I noticed that the K3 randomly keyed up and briefly
> transmitted full power CW every few seconds while listening. This happened
> with no action from me. I unplugged the paddle, mic, and headphones.  None
> of these had any effect on this behavior. Tuning the K3 made this
> uncommanded keying speed up and occur at a rate porportional to the tuning
> rate.  This problem occurred abruptly.  The station had been working fine
> for months before this occurred.
>
> This behaviour stopped when I powered down the P3.
>
> In the days following I went through the K3 menus, certain that I had
> unintentionally selected something that cause this behaviour.  I found that
> my transmit power setting for transverters was set below 1 miliwatt;
> sometimes as low as  0.1 milliwatt. When I restored the XV drive power
> setting to zero dB the uncommanded keying stopped, even with the P3 powered
> up. Hmmmmm........
>
> Now there's a different problem:  The P3 does not  initially display the K3
> frequency upon K3/P3 power up.  Instead it shows the "#" symbol in the top
> center of the screen. When this happens the P3 does not display the green
> or purple frequency bands of the "a" and "b" VFO on the scope.  The
> spectral display seems to be unaffected.  This condition can sometimes be
> "fixed" by changing bands, especially when changing to a band that requires
> an XV transverter to be powered up, but not always.  Band change
> communication with the KPA500 occurs normally with or without the P3
> powered up. Usually this P3 display behavior goes away and the P3 behaves
> normally after 30 minutes of operation.  I seldom see it after an hour of
> operation.
>
> The station is all single point grounded.  Both the K3 and KPA500  are tied
> to this single point ground.  P3 and transverters are not seperately
> grounded.
>
> The K3 has firmware revision 4.42. The P3 has firmware revision 1.09.
>
> Apparently there is some marginal communication issue between K3 and P3.
> has anyone observed this odd behaviour?
>
> 73, Bill
> W7QQ
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

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Please help support this email list: http://www.qsl.net/donate.html