several months ago, I made a GPSDO, the PCB designed by me, all the bom list select by me, also soldering by me, very cheap, very simple, pls check the attached diagram, what you need is a SMA to MCX cable, and a GPS antenna (active, 3V), I write a simple operating guide for it, I just list it within Ebay (test result is quite stable, tolerance is less than +-1ppb);
actually RSP device is very good in decode the digital RF signal, the only problem is it need a external reference signal, otherwise sometime can not decode it if your clock’s tolerance is more than 50ppb;
the testing use the Rubidium as the reference, 100 seconds mean value, and Max-Min frequency as the P-P value.
