Getting better signal coverage.

[T.ALLRED]

Could anybody tell me if I could get 5 miles out of a SSTran AMT3000 if It was grounded perfectly, Considering if I had rocky, Alabama clay soil?

[Rich]

Here is an estimate for a 3 meter vertical radiator with its base at ground level using a nearly perfect r-f ground, as based on the FCC’s propagation curves. The more typical r-f ground used for Part 15 AM would reduce these distances significantly.

INPUT DATA:
Loading Coil Resistance ~2 ohms
Frequency = 1,600 kHz
Tx Output Power = 80 mW
Conductivity = 3.0 mS/m

RESULT:
Contour level > Distance to contour
5.000 mV/m > 0.0322 miles
2.000 mV/m > 0.0805 miles
0.100 mV/m > 0.9448 miles

Receiving medium-wave AM signals of ~0.1 mV/m and less may get objectionally noisy, even when using a good car radio. Signals of 2 mV/m and more probably will be usable on a cheap clock radio inside a home, at least at many locations in rural areas, and those not within the industrial/commercial zones of cities.
//

[scwis]

Seems unlikely, considering your Alabama location. This link:

http://part15.us/node/70

will give you some information about ground conductivity which is the relevant aspect of soil quality for broadcasting. I’ve heard of folks lucky enough live on soil rated at “30” to get out well over a mile, your location might be somewhat less conducive to that.

[kk7cw]

The cry of those who have gone before…..”Get Real”. 5 miles is neither realistic or probably legal under Part 15 rules. Rich is correct. With average ground, a mile or so is the “best case” signal coverage. After that, begin planning your next transmitter site for a network of stations all synch’d together. Nobody said broadcasting was cheap. Good Luck.

Marshall Johnson, Sr.
Rhema Radio – The Word In Worship
http://www.rhemaradio.org

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