[crote]

There are some subtle differences. The Jackson Labs and Microchip boards both have a diagonal "swoosh" and a "do not touch" icon on the metal clock casing, a u-blox branded GPS receiver, and partially-filled mounting holes. The Viavi board has a blank clock casing, unbranded GPS receiver, and fully drilled-out mounting holes. But yes, all three are using a virtually-identical PCB.

Judging by the misaligned capacitors(?) on the Viavi board, it is almost like the Viavi one is an early prototype, with the Jackson Labs one being an early production version and the Microchip one being the current production version. I have no idea how that would work out acquisition timeline wise.

But yeah, hardware companies are rather acquisition happy. When designing hardware it is very common to come across datasheets with an "X is now known as Y" cover page stapled onto it. Heck, every once in a while you'll even come across a datasheet which is obviously scanned-in, for a brand which hasn't existed in three decades - and the chip will still be in production!

[opello]

I did dig into this a bit more the other day and learned that the "main RF can" is the cesium oscillator module. The history there was pretty interesting! The early ones I found were the Symmetricom Quantum SA.45s[1,2] which included a pretty entertaining thread here[3]. There were several levels of quality and function in the family of products which have been discontinued in favor of the MAC-SA55[4], and I wish I could find where I saw that recommendation... It's a rubidium, instead of cesium oscillator, not that I know enough about these things to concluded one should be better than the other but my impression was cesium was higher precision.

[1] https://www.gpsworld.com/wirelesstimingnewssymmetricom-offer...

[2] https://www.si.edu/object/symmetricom-chip-scale-atomic-cloc...

[3] https://febo.com/pipermail/time-nuts_lists.febo.com/2021-Jan...

[4] https://www.microchip.com/en-us/product/mac-sa55