I also dedicate one powerhouse to each powermaster.
If you are simply running track under scenery you should be ok with the signal. The problem arises when one runs track underneath other track. The signal from the elevated track mixes with that of the lower track increases the signal frequency and confuses the locomotive. You will know you have an issue if the locomotive stops and the front light starts blinking.
Running a ground plane under the elevated track connected to earth ground stops the signal from propagating below the track. Some use aluminum or copper sheets. Others simply lay wire (coated or un-coated) along side of the track.
I have heard of issues running through metal bridges but again connecting the bridge to earth ground solved this.
There is article written by the NJ HiRailers in Patterson about this issue and how they solved it however I can not remember which OGR issue it was in. It was at least 5 years ago.
Joe
