Total posts : 45366
PhilB’s point of a proper ground for lightning protection is valid, however as long as the ground lead issue debacle is unresolved and remains undefined with clarity from the OET/FCC, it is and will remain just that…a debacle.
Not to re-open old wounds, but this is why the choke along that ground line will help reduce radiation from that long ground line. Though not entirely, it is better than no choke and a ground line radiating more than the intended radiating element, be it a monopole or Isotron.
However if the Isotron is set up 1 meter off the ground, there is no worry as every certified Part 15 device is tested 1 meter over an artificial ground system in the testing chambers with the DUT connected to that artificial ground system either through the table which is metal that the DUT is sitting on, or through a wire connected to that artificial ground below it.
Regardless, using an Isotron or a loaded 3 meter monopole on a roof installation, your going to face the debacle endless loop argument over the exceeding 3 meter limit thing and ground line radiating debate.