Then, an easier way; 2x SDR boards (Hermes, Orion, etc.), sharing clock, in same enclosure, let´s say back-to-back.
This way you get two coherent boards, with two coherent receivers and two coherent transmitters, starting point for beamforming.

GPS is not mandatory.

That is why both ADCs need to be clocked from the same sample clock, and clocked at the same time, i.e. there should be no differential delay between samples. So, there isn´t any way to clock two separated SDR ? Perhaps.... a NCO ? https://en.wikipedia.org/wiki/Numerically_controlled_oscillator

Hi Scott, all, I remember when you said: As a group we are still not fully exploiting the synchronous receiver capability inherent in these radios. Instead we continue to rely on constructs such as so-called "phasing harnesses" or "array controllers", all of which use coaxial del...

Hi,

I think the non-coherent diversity system is similar the one called "voter" used in legacy VHF repeaters.

73, Maximo