The nose-to-nose calibration technique 1-4] was proposed in 1990 to determine the impulse response of broadband oscilloscopes. Finding and correcting the response of these high-speed oscilloscopes is important because the typical response time of their internal sampling circuitry is of the same order as the signal transitions of many highspeed circuits under test. To measure the amplitude response of broadband (defined here as 20 GHz or greater) sampling oscilloscopes, we currently use the "swept-sine" method 2, 5], where a series of individual tones of increasing frequency and known power are fed into the oscilloscope.