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Gerry: “I do believe that this church grounding issue was because of a complaint. Somebody likely noticed the range of this transmission and reported it.”
Physics shows that a ground wire or any assembly of “leads” and/or conductors of ANY gauge will radiate when connected together between the tx ground terminal and the true r-f ground reference (ground rod, water pipe, radials etc). In virtually all cases it will radiate much more field than the 3-meter whip above.
The length of the conducting path to r-f ground was the basis for the church citation, but the underlying reason for limiting the length of that conductor in the first place (15.219) was to limit the radiation possible from unlicensed AM systems.
Now following with comments to some of the statements in your post, reportedly from the Rangemaster site:
Rangemaster “We don’t feel that in most cases, a properly designed ground system will add significantly to the overall radiation of the system, …”
There is abundant evidence in antenna engineering textbooks and elsewhere to show that radiation from a long conducting path to ground is a significant, and often the largest source of radiation from a Part 15 AM antenna system. If the meaning of “a properly designed ground system” as used in the paragraph above is one where the total radiating length of the conducting path to the buried r-f ground plus the length of the whip is 3 meters or less, that should be stated. But I don’t think that configuration is described elsewhere on the Rangemaster site (correction invited). The installation drawing on the Rangemaster site shows the tx/antenna installed on a rooftop, with a long ground conductor.
Rangemaster ” We have no problem calling the tiptop of your ground wire at the transmitter binding post “ground” as long as you use a massive wire, (#12 or #10) intended for grounded purposes.”
Rangemaster may not have a problem with thinking of the top of a “massive wire” as ground, but that concept is not supported by physics. Even though the top of such a wire may be near “ground” potential for direct current, it has considerable resistance to the flow of the r-f energy in it, that results from the coupling of the wire with space, ie, because it is acting as a radiator. So the top of that wire is NOT an r-f ground. The whole length of that “massive wire” radiates until it enters the physical earth.
Rangemaster “..however if your system requires it, we stock an RFI filter that you can place in series with the ground terminal of the transmitter (needs to be placed physically right at the transmitter ground terminal to be effective) that will suppress RF radiation from the ground system. Just let us know when ordering and we will include the filter.”
The r-f filter is good, but how are users to know whether or not it is needed? That takes an understanding of antenna systems that few Part 15 operators would be prepared for. And how about r-f filters for the power and audio leads — they also will radiate unless filters are installed in them.
These quotes reportedly from Keith Hamilton/Rangemaster use phrases like “we at Rangemaster feel,” “we do not feel,” “we have no problem with”, “it is reasonable to allow,” “will add significantly,” “and “I have been told.” Such statements shift responsibility for using the information they apply to back to the reader, and wouldn’t give anyone implementing such advice any reliable relief from possible FCC action.
Please note that I am neither anti-Rangemaster nor anti-Part 15. I am neutral. The purpose of my posts is to supply technically valid information to be used as its readers see fit — which should offer a positive and encouraging benefit to those wanting to better understand Part 15 systems.