Microwave Modules T432/144R transverter


Hi all.
I picked up at a rally - remember those! - last year a MM 432/144MHz transverter at a very cheap price!
It has two xtals in it, one at 101MHz and one at 101.4MHz (along with a 116MHz one as well). These will obviously give the needed 1.6MHz shift for repeater operation. Problem is how do you select the appropriate xtal as there are not the usual two toggle switches on the rear over the power DIN socket. However the two DIN pins 2 & 4, normally a "not connected".  are connected to the pcb and I suspect that the repeater shift can be remotely set. The two pins in question have zero volts on one and 8volts on the other.
Question is does anybody know how these pins are connected to remotely control the repeater shift.  As the unit stands with no external connections to either pin,. 144.2MHz in gives 432.2MHz out
Hopefully somebody might know or even have a circuit/manual for this version.

Martin G3ZQU

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