I think I had the only DX7 present. But shadowing is something that dual and differently located RX's was supposed to cure. Unless the remote RX's freq became occupied and the primary RX shadowed. At least this isn't the 70's during the CB craze when you had a lot of JA's with 1000 watt linear amps on their Radioshack CB swamping the 27 mhz band & overloading the front end of 72 mhz RX's.

We were on a military base at the time.

Roy