Hi Brian, I have my U3S on a 10M beacon frequency. And I use the QRP-Labs PA kit. The shaping is accomplished on the PA kit assembly. So on your U3S if you don't use that particular PA you would not select any shaping options in the U3S menu. And there would be no shaping accomplished as far as the U3S goes. There is an app-note? AN-005 on the website that deals with your intended situation . Best of Luck Bill KN8DMK
