Neither. The signals will not be present at the same time. However both share the crystal filter and some following circuitry. At present the signals are dot ored together. The one being of 2K source impedance and the other very high by comparison. I was hoping to improve the match to the filter in receive mode and isolate the two signal sources..
Dot Oring with two switching diodes sharing a common pull-up resistor would be a lot simpler. You could still buffer/equalize the levels upstream of the diode gate.