Once the master box was mounted, we experienced a high noise level on 80M. After troubleshooting, we discovered a ground wire was needed between the master circuit board and the antenna ground. I need to go back and understand why this was required. After a jumper was connected, the noise level just about disappeared.
The 'on the air' tests were great! For the first time ever, we were able to quickly switch between the RX antennas. We tuned in several AM broadcast stations (e.g. 1500AM) around 4:30 in the afternoon. As we switched through the various antennas, we could see the signal strength change and peak as expected. At one point, we could switch to the SW antenna and listen to a station in Florida. Then, switching to the West antenna, we could listen to a different station in the mid west.