[Elecraft] K3 - communication failure after KIO3B upgrade

[Lyle Johnson]

Carl,

A couple of thoughts.

1) Losing communications with the Y cable plugged into the KIO3B but not 
having BOTH DE-9 connectors attached to the P3 will result in no 
communications.  The KIO3B senses the Y cable and routes the USB side 
communications to the P3 which then routes signals to the K3.

2) Be sure the cable is fully seated into the jack on the KIO3B. The 
plastic lock should "click" into place.  You can verify this with a 
gentle tug on the cable after it is inserted to verify it is fully seated.

3) Be sure the P3 is set to 38,400 bps on its serial ports.

4) If the cable is fully seated and the P3 is set to 38,400 bps and you 
still have the problem, I'd suspect the Y cable being defective.  I 
don;t know if the schematics for the cable are on the website or 
supplied with the cable to assist you in troubleshooting the cable if 
you so desire, so it may require a call to support on Monday, or an 
email directly to them.

73,

Lyle KK7P


> Maybe the combined wisdom of the group will be able to help before I send
> this to Elecraft support.
>
> I installed the KIO3B upgrade in my K3. The USB interface from PC to K3
> works but only if you don't plug a cable in the RS232/P3 jack. The RS232
> connection to the P3 isn't happening...