Thanks Zack, that does not sound very viable to me.
As most of the precise clock sources available are mostly 10MHz units, it would have been nice to highlight on the spec sheet, that those are unusable, so the clock in can practically only be used to sync Minis to each other. Also highlighting that this needs a HW mod would be informative. If I would have known this, I would not bought the Mini… I guess the “big” LimeSDR can be driven from a 10MHz source without HW/SW mods.
I think the best what I can do is to sync my VSA to my 10MHz ref, measure the Mini with it, and trim the VCTXO as close to it as its possible. FYI, out of the box, my Mini has a 12kHz freq error on 2GHz…
Can you tell us what DAC do you use now, and did you needed to change anything in the SW as well?