[Elecraft] K2 key autodetect problems

[Don Wilhelm]

Chip,

A string of dashes means somehow the dash line is being activated (or 
grounded) - normally the ring contact on the key plug unless you have 
reversed the paddles.
Do you have the key plug inserted all the way?

Put a bare stereo plug in the key jack and read the voltage on the tip 
and ring - you should see 5 volts.

Look at the R1 and R2 resistors on the RF Board next to the key jack, 
they should both be 220 ohms (they may be easier seen by removing the 
left side panel).

If that is all good, consider replacing the diodes with Schottkey diodes.

73,
Don W3FPR

On 3/27/2018 2:36 PM, Chip Stratton wrote:
> I have the external circuit using two diodes to allow the K2 to detect when
> a straight key is used instead of the paddles. Occasionally with the paddle
> plugged in but not keyed, the K2 will  spontaneously start sending a string
> of dashes. This will terminate, sometimes only briefly, when I do key the
> paddle. It happens even when K2 transmit power is turned all the way down,
> and I've never had trouble with RF in the shack.
> 
> Both diodes test fine, at 0.64V drop forward, and no detectable leakage
> reverse. The paddle also tests fine, both lines open when it isn't being
> keyed, and likewise the autodetect box shows no shorts to the ohmmeter.
> 
> Ideas?
> 
> 73
> Chip
> AE5KA
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to donwilh at embarqmail.com
>