3 comments
No mention of the cost of the CSAC GPSDO (only that it's "not cheap").<p>Too bad you couldn't hack the Americium module from a smoke detector and create a DIY atomic oscillator. Cesium seems to be preferred. (And I know nothing about this sort of thing.)<p>(EDIT: chatting with an LLM… I realize I had assumed that "atomic clocks" meant radioactive and so suggested Americium because it is easy to obtain. LLM <i>schooled me</i> and suggested "Rubidium oscillator modules" instead since they come up for a few hundred dollars or so on eBay. Still not the DIY approach I had hoped for—I think I am still channelling the old "Amateur Scientist" column from <i>Scientific American</i> from the day.)
I don't believe it's necessary to have multiple GPS antennas (one per device), unless signal path redundancy is required. A good GPS distribution box like from Time Machines or GPS Source can split the antenna signal to many devices without an issue.<p>A signal distribution box used from eBay is a lot cheaper than a good outdoor GPS antenna!<p>Though if you have enough cable and enough antennas already, no harm in having a little array like in OP.
I wonder how, if at all, you can improve precision with 4 stratum-1 clocks like he author has.