[TowerTalk] modeling antennas near AM stations

[jimlux]

Looking over that proposed rule..
"(c) Proponents of construction or significant modification of a tower 
within the distances defined in (a) and (b) herein of an AM station 
shall examine the potential effects thereof using a moment method 
analysis. The moment method analysis shall consist of a model of the AM 
antenna together with the potential reradiating tower in a lossless 
environment. The model shall employ a simplified version of the 
methodology specified in § 73.151(c) of this chapter. The AM antenna 
elements may be modeled as a Federal Communications Commission FCC 
08-228 series of thin wires driven to produce the required radiation 
pattern, without any requirement for measurement of tower impedances."


This seems pretty straightforward, but I don't know anything about the 
"simplified version of the methodology in 73.151(c)"

Anyone have a "25 words or less" summary of what this kind of model is? 
Each tower modeled as a single wire of appropriate diameter, and driven 
with a current source of the appropriate phase?

And when they say lossless environment, does that mean "perfect ground"?


There is, or used to be, a nifty site that had all the antenna info for 
broadcast stations, at some level of detail (physical and electrical 
height of radiators, phasing, physical positions), and it would 
conceivably be pretty easy to make a script that would extract this and 
generate the required NEC deck for a ham to use.  (or, for all we know, 
the stations already have the NEC model in their application)