When Windows is started, The operating system checks the Device Manager to see what is set up on your system. When it sees the serial ports (both real and USB to Serial) Windows exercises all the output lines of all the serial ports on the system to test them. This can result in a very quick keying of the K3 (mine does it 3 times). If the K3 is in SSB or CW mode there will be no output but if you have a linear on during this time it will see a PTT input during the port test.
I always have the K3 (and linear) off when I reboot or turn on the computer. I also have the linear in stand by or off before I turn on the K3. There are many rigs which will have a short transmit burst when powering up, K3 included. Unless you are running an analog rig your rig stands a good chance of doing the same thing 73 Dave KD1NA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html