This is what the band decoder box looks like once mostly completed. The cable on the top right are the relay control outputs. The bottom right DB25 cable is the band data passed along from the so2r box. Power comes in on the left, and has a jumper to pass power to the so2r box.

On the top cover are the band indicator lights, connected to the decoder board via a harness made up from Cat-5e twisted pairs. The band data comes in from the source into the CD4028 chip, which drives the N4401 NPN transistors. The transistors will be used as sinking switches to drive the relays as needed.

Another innards look.

Another look at the innards.