[BC] Part 15 LPAM Questions?

[WFIFeng@aol.com]

In a message dated 09/11/2006 09:19:32 AM Eastern Daylight Time, 
rfry at adams.net writes:

> Frequency (MHz) 1.5
>  Wavelength: 656 feet
>  Diameter of antenna in inches: 0.5
>  Antenna diameter in degrees: 0.022865854
>  Height of antenna in feet 9.84
>  Antenna height in degrees: 5.4
>  
>  Rr = 0.093461538 ohms
>  Xc = 2,833.77 ohms
>  
>  Using a larger or smaller OD radiator of that length changes its input 
>  reactance, but not its radiation resistance.
>  
>  So I think the radiation resistance for this configuration is bit smaller 
>  than in your earlier post, not ~ twice as great.

I've seen some discussion in the past about using 55 gallon drums, stacked, 
to make an ~10' tall antenna. Obviously, this would be quite unwieldy... so 
what about an equivalent, using several copper pipes in a "cage" form? Would the 
FCC consider each length of pipe, thus rendering such an antenna illegal as 
defined in P15? (Then we'd be back to the barrels.) I'm just curious how the 
numbers would work for such a "fat" radiating element as that.

Also, seeing as only about 1% of the power is being radiated by such a short 
antenna, (thus only 1mw) how does this explain the verified coverages of up to 
a mile using the Rangemaster transmitters? Can it all be caused by the ground 
structure radiating? (Mounted on an existing steel frame structure, such as a 
tower or large billboard, storage tank, etc.)

Willie...