Does anyone have any nuts and bolts (disassembly?) experience they can share regarding fixing a Datum 1000B pn 05818-115 (4x10MHz) which has a manual frequency pot and which will not adjust to 10,000,000.000 MHz? It will actually go as low as “10,000,000.2890”, but no lower. (The unit does not respond to EFC voltages.) Many thanks. Jim Robbins