Chris. AM alignment is critical in the 751. Try readjusting R159 [AM carrier level adjustment] Set to lowest level and while listening to your IF monitor increase the pot until you notice distortion. Then back in down a click or two. When properly set and the Power control set fully CW, your AM output should be about 40 watts. My 751A sounds nearly as good as my DSP rig. Good luck. 73, John W5GI