Is WSRO-AM 650 Testing Its Modest Power Increase?

Scott Fybush
Sun Jun 15 09:17:06 EDT 2014

On 6/14/2014 4:05 PM, Paul B. Walker, Jr. wrote:
> Part 15 is 100 MILLIWATTS.. 1/10th of 1 watt.

This is a common misconception, and trotted out with certainty by lots 
of people who like to sound like they know what they're talking about.

It's also wrong.

Section 15.209 of the FCC rules specifies a maximum field strength 
(24000 uV/F(kHz)/m at 30 meters). It does not specify the power output 
level that is to be used to achieve that field strength.

15.221 provides for the possibility of slightly higher power levels in 
order to cover college campuses, provided field strengths do not exceed 
a certain very low limit at a specified distance outside the campus.

For FM, the limit is 250 uV/m at 3 meters.

Nowhere in the FCC rules does the mythical "100 milliwatts" appear, no 
matter how many times this misinformation makes the rounds on message 
boards and mailing lists.


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