This may be too simple to work right. Yet, the way digital circuits mix frequencies it appears to be possible. Only thing I have Flip Flops but no AND Gates to try this now.
Anyways the LO IN is phase shifted with a 74HC74 Dual D Flip Flop and the QSD section is merely a Dual AND Gate IC. What do you think? Impossible? 5 0/50 chance?
