Total posts : 45366
Neil wrote: If the carriers are synchronized, as I think they can in the Rangemaster, then … there will be nulls in the patterns where the signals overlap which will appear according to the listener’s position.
This is an important observation which (apparently) is unrecognized by Rangemaster.
The link below leads to a plot of the total radiation from two identical Part 15 AM systems located 2 km apart, whose antennas radiate equal power, at an identical r-f frequency and phase.
Directional AM broadcast stations use forms of this technique to generate the radiation patterns they are required to have by the FCC. Of course, all of those patterns have far fewer nulls and lobes than in this scenario, because the individual radiators at AM stations are much closer together.
If the r-f phases of these two Part 15 AM systems in the link are not accurately locked then the pattern shown would change constantly.