I think we finally have everything defined correctly. You and I agree.
The design of this radio is impressive. I've had several home built receivers where switching between usb and lsb involved changing the if frequency to move from one side of the filter to the other. Since most simple filters are asymmetric (the slope on the high side and the low side are not the same, the two never sounded quite the same going from usb to lsb.
This design seems to eliminate this problem in the if chain so the bfo remains constant and the filter response is the same on both usb and lsb.
Nice.
tim ab0wr
