RCA rate the 4CX250B at 295 watts PEP output through a 95% efficient tank circuit with 2000volts on the plate and -30dB 3rd order products, although it doesn't say if that is -30dB with respect to one tone of a 2 tone signal or -30dB with respect to PEP. Nobody has mentioned measurement uncertainty in this discussion, either...... 73 Peter G3RZP