I am looking to add to my tranaverter collection soon and the FT-817 I have is bone-stock. Non-ND, and still had the original wrap on it. Got a good deal on it. As I venture to 10 GHz and beyond I want at least a reasonable chance of being on frequency. And I'm looking at aircraft scatter and digimodes that really need it. The 817 has a TCXO-9 add-on to supposedly get it to 0 5ppm. If I went to a GPSDO I could get that into parts per billion. But thats not plug and play. An Australian company made such a board, called the XREF. But they no longer produce it. Curious if I am overlooking others. And second to that, I am assuming using that GPSDO means theres no need to upgrade to the TCXO... unless I can't get a GPS lock? I will, of course, lock the transverter. But I would like to lock the rig as well.