How to unballance this single balanced mixer?

Hi, how can I unbalance this single balanced mixer so that it can detect AM on down conversion or produce AM if used in up-conversion in a direct conversion transceiver?
LO is connected to the 4.7nF left side.
Is it enough to remove one of the two diodes, or...?

I suspect that if I apply 9v DC through a limiting resistor (say 1k?) in the left points of the diodes, one diode will conduct DC to ground whereas the other not. So it will be effectively one diode action then in the RF. Is that true?