[Elecraft] K3 Goes to TX on Turn ON

[Don Wilhelm]

Paul,

The K3 does not use RTS or DTR for communicating with the PC, only RXD 
and TXD and Signal Ground are used.  So the setting of PTT - Key should 
have no effect on PC to K3 communications.  I suspect a serial port 
problem or a serial cable problem.

Since you have real serial ports on your computer, try using a known 
good serial cable and take the P3 out of the loop (disconnect the P3 and 
connect RS-232 direct to the PC - no "Y" connectors or other 
complicating factors).  Then try to connect with K3 Utility.

If that does not work, suspect the PC (because you have trouble 
connecting to the KPA500 too).
Since the USB connection to the KAT500 does work, try using a USB to 
Serial adapter - preferably one with an FTDI chipset.  If that works, 
you might try reloading the drivers for your add-on serial cards.

73,
Don W3FPR

On 10/24/2014 4:09 PM, paul ecker via Elecraft wrote:
> I changed K3 PTT-Key to "OFF-OFF", that seems to have solved TX on turn on problem. But now - not sure if related- K3 will not talk to PC serial port. I have two 2 port serial cards installed my Win 7 64 bit PC. I tried cable from K3 in all four and can't get it to connect. Also cannot get KPA 500 or P3 to talk to serial ports. I tried another serial cable- same problem. KAT 500 using USB connection does interface with PC OK.
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