John, See the K3 manual menu listing for LIN OUT. Set that menu parameter to "=PHONES". The level will be adjustable with the AF gain. Also use the MONitor knob to adjust the TX level. Yes, RX audio will also be present. 73, Don W3FPR On 12/21/2017 9:34 AM, John Simmons wrote: > Is there a way to monitor TX audio via the LINE OUT jack?