From Adam`s blog:
I was caught by surprise out in the field the other day, when my new Kuhne MKU 10 G3 432 appeared to not work. But it worked fine on the shack bench.
Kuhne are very secretive about the PLL board, as no schematic is supplied with the transverter module, so it was going to be difficult to look for answers there.
(And the schematic supplied with an MKU 10 G3 432 is actually that of the MKU 10 G3 144 variant, not the 70cm version. It’s close enough though.)