Hi, I can send commands PC to radio but K3 don't send information to PC. I checked RFCs, every had 4,7 ohm. There was -8,4 V at U1 pin 8. U1 is not hot. Is U1 broken? juha - oh6os -- View this message in context: http://elecraft.365791.n2.nabble.com/k3-rs232-problem-tp5429452p5440332.html Sent from the [K3] mailing list archive at Nabble.com.