To clear up the confusion on this, let me explain how the preamp works. In a radio with a single receiver, you can decide to use the preamp on 6m and not use it on 40m. In the FLEX-6300, you have the option of listening to two bands at the same time. If you choose 6 and 40, you really want the preamp on for 6 and the attenuator on for 40 for almost all band conditions. Since there is a single SCU in the radio, you have to decide whether you want the preamp on or off. So to accommodate listening to 6 and 40 at the same time, the preamp has slope to it that provides gain on the high end of the spectrum and attenuation on the low end. So the panadapter reads out the effect of the preamp on the band you are on.