Does anyone know if you can hook up two 990s together? I know you can hook up a 990 and a 993 but can you have two 990s hooked up? I’m curious because I found a 990 for sale at the normal price and not $1000 or more and I’m thinking about getting it if I can run it with my existing 990.
No, you cannot have 2 990s (Legacy bases) connected together- nor would you want to.
You can use the CAB2 remote (example multiple CAB2 remotes talking to one single Legacy base), and you can setup 2 entirely different layouts on totally different channel IDs for the remote to base coms, but no, putting 2 990s (Legacy bases) and wiring them up- either serial connection or worse radio "U" wire is a conflict.
Again, you can use the CAB2 from the set- but even just using the base as a charging station, you would have to change the channel to not conflict with your existing base- and you would not "wire it" except for power.