I have come across an issue with the frequency output from the GPS module. Because the 10MHz signal is derived from a 48MHz internal oscillator, the signal contains quite a lot of jitter.

I may have to use an OCXO together with an FLL instead to get a usable output signal.

I have also been working on a low pass filter to derive a 10MHz sinusoid from the square wave output.

To buffer the signal between the input of the filter and the GPS module I am using a 74AC14 inverting Schmitt trigger. To get a good termination for the LC filter I followed the output of the 74AC14 with 49.9 Ohm resistor.

Unfortunately at 10MHz there's quite a bit of ringing on the 74AC14 output waveform that feeds through to the output of the filter. I may have to add another LC stage to improve the performance.

I'm beginning to think that I may convert the Extron simply to a 50 Ohm analog distribution amp and layout an extra PCB for the GPS unit, a micro and a TCXO, similar to what Nick Sayer has done in another project on this site.