[BC] Part 15 LPAM Question?

[Mark Humphrey]

On 9/8/06, WFIFeng at aol.com <WFIFeng at aol.com> wrote:
>
> If I had the $1,000 to spare, I would get a
> Rangemaster and plunk it there. IMHO, there really is no better place to
> operate it.

Here's a Part 15 "loophole" to think about.

The rules say that an unlicensed AM transmitter must not exceed 100 mW
PA input power, and the total length of antenna and ground must not
exceed 10 feet.  However, the maximum number of transmitters operated
by one individual is not specified.  We know of some folks operating
several Rangemasters, spread out around a community.

Now, what's to stop someone from installing several 100 mW
transmitters (each with its own 10 foot antenna) on the same lot,
driven from a common frequency reference and modulated with the same
audio, strategically placed to form a directional array?  For example,
five in line, with proper spacing and phasing to produce a main lobe
that's aimed into town?  Someone with enough real estate could even
build a Part 15 model of the KLIF 12 "tower" night array!

Or, install three commonly-phased Rangemasters in the form of a
triangle, perhaps 25 feet apart.  At such close spacing, I would
expect the fields emitted from the three antennas would reinforce in
all directions, enhancing the omnidirectional ERP by at least 3 dB.

Has anyone here tried this?

Mark