hopefully far away from the offending router which will have transmitter power measured in MILLIwatts.
I'm sorry, where did you find the EIRP of a PLT device with an undefined 'antenna' consisting of the entire jumbled mess of power wiring attached to it?
We are not talking about regulated, engineered radiators, we are talking about the unregulated, illegal radiation of poorly thought out garbage. These devices are known to cause interference for hundreds of meters, and the more of them used, the greater the area they affect.
I never menitoned a PLT device - we established that a couple of responses ago, and the term EIRP is well above my intellect.