K3-P3 duo result in tx keying via VFO turning for 30 seconds

[K7VO]

For about 30 seconds any movement of the k3 VFO causes a chatter like keying (tx led lights and pwr output shows) of the rig. Then it disappears and only can be reproduced after the rig has "cooled" for half an hour and turned back on. Vox off. K3 grounded. No ground attachment for P3.Ideas?
K7VO

[Ignacy]

I use Microham CW keyer with N1MM. Twice during CQWW, the keyer started sending fast low-weight CW and could not be easily stopped. Restarting N1MM did not help; keying was still erratic. Strangely, keying from within the microham software was fine. Restarting the microham software cured the problem.

I attributed it to RF feedback although I never experienced one before with Microham devices.
This was my first contest with P3 and 4.22.

Ignacy

[Joe Subich, W4TV-4]

Ignacy,

I don't understand where this would occur.  The P3/K3 is "downstream"
from the CW Keyer and should not enter the equation.  However, there
is only one weight setting ... it is set from the microHAM Router
software and can't be changed by other software ... which applies to
all output from the WinKey chip no matter what the source.

Are you sure you are not bypassing the keyer by configuring your
logging software to use PC generated keying on a serial port DTR
line?

73,

    ... Joe Subich, W4TV
        microHAM America, LLC.
        http://www.microHAM-USA.com
        http://groups.yahoo.com/group/microHAM


On 11/29/2010 11:00 AM, Ignacy wrote:

>
> I use Microham CW keyer with N1MM. Twice during CQWW, the keyer started
> sending fast low-weight CW and could not be easily stopped. Restarting N1MM
> did not help; keying was still erratic. Strangely, keying from within the
> microham software was fine. Restarting the microham software cured the
> problem.
>
> I attributed it to RF feedback although I never experienced one before with
> Microham devices.
> This was my first contest with P3 and 4.22.
>
> Ignacy

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[Ignacy]

I have no idea why this happened. It happened only twice during the contest so repeating is difficult. I am also not distributing blame as Microham devices have been very good for me.

With K3 anything can happen.  Yesterday, after RF gain calibration, the RF gain control did not work. The culprit was K3's utility of Sept 2010. The Nov utility made RF gain working again.

Ignacy