You may get a shallow dip if the plate is tuning a harmonic instead of the fundamental. This may be a bandswitch problem. Or something really messed up in the output ckt. 73 Bill wa4lav -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com