Philly 50,000 watters - truth or fiction?

Are there really 50,000 watt FM radio stations in Philadelphia?

I said as much in a story yesterday about low-powered FM stations - then was called on the carpet by an advocate/activist for the cause, who demanded  to know where I came up with these  cockamamie numbers. He aimed to shame me with the "true" stats - the authorized power outputs for Philly FM stations - topping out at 27,000 watts (for WUSL Power 99) -  he found posted on the Federal Communications Commission web site.

But playing the numbers game is not so cut-and-dried. Broadcasters here and nationwide,  many claiming  50,000 watts for marketing purposes, calculate their power with a "real life" operating scenario and methodology that makes a whole lot more sense to me - and to their advertisers.

Then, for clarity's sake, these stations tack the phrase "effective radiated power" (ERP) onto their stated power claims.

My fault in yesterday's story was in making an "apples versus oranges" comparison – noting that low power, non-commercial  community stations top out at 100 watts – their FCC -authorized transmitter limit – in the same breath as stating that commercial stations go to 50K.

Effective radiated power calculations  (check out the Wikipedia page)  take into account  not only the authorized transmitter output, but also the all–important location and height of the station's antenna (which the FCC also must approve), the surrounding geography, the position of the station on the dial and adjacent channel interference – how closely stations are bunched and  how close/far away is the next station licensed to operate on the same frequency.

A 15,000-watt station with its antenna "stick" atop a  center-city Philly building  can be at a significant disadvantage in real world "reach" compared with a 15,000-watter that's pumping it out from the antenna farm in highest-elevated  Roxborough.

Radio engineers' ERP  calculations also take into account that signals are simultaneously sent out at  the authorized power level two ways   - with  both horizontal and vertical phasing. And I've got a funny story about that, demonstrating how/why those numbers really should be "summed."

For a decade (my young adulthood), I hosted late night  weekend radio shows on WMMR, under titles like "The Last Radio Show" and "All that Jazz." Back then, a DJ had to earn a Third Class operators' license from the FCC to legally operate "the board" (controls) – a license requiring some knowledge of broadcasting technology (and a test) to obtain.

As part of my shift, I also had to take and record transmitter meter readings – which measured the vertical and horizontal power outputs separately.

One late night, flashing red lights and a loud alarm went off in the transmitter room. The meters suggested that the transmitter had essentially  blown up. It was now only putting out a signal in the horizontal plane. I called the head engineer. He said he'd try to remotely switch to the backup transmitter, that in the meantime I should stay put and pretend I was still on the air, to keep on playing tracks though he said we were officially "down."

I confirmed on a studio radio that we were off the air. Heard nothing but static. Then, to amuse myself, decided to play all the tracks that mom and the FCC said I couldn't – like unexpurgated Lenny Bruce and a charming Harry Nilsson ditty that goes "You're breakin' my heart, you've tearing it apart,  so f*** you."

Suddenly, all the phone lines lit up – with callers from Southern New Jersey who were still picking up the horizontally-oriented half-a-signal!

"Great show man." "Best ever."  "Keep it up."

Thank heaven, nobody complained to the feds. Would have cost my job and a big fine to the station.