>From ALAIN FG5GI I have an old Ten Tec argonaut 509 and i want to modify for psk : can I find a narrow filter ( 500hz ) to remplace the ssb fiter ? Merci for help. -- FAQ on WWW: http://www.contesting.com/FAQ/tentec Submissions: tentec@contesting.com Administrative requests: tentec-REQUEST@contesting.com Problems: owner-tentec@contesting.com