Re: WHOM and other Superpowered FMs
> On Doug's list, he lists many West Coast stations higher,
> even though as much as half their signal falls over water.
> WHOM's signal is nearly all over land. And since the area
> around Mt. Washington is so mountainous, he doesn't give
> WHOM extra credit for being so high above sea level, since
> some of its territory is right at the edge of the ocean.
>
> Two of its biggest sales areas are Portland ME and
> Portsmouth NH, right on the coast. Never the less, you'll
> enjoy reading the list.
Doug's list is correct for the calculations that Doug is making, which reflect how much more power a station uses than the maximum now allowed for that station's class.
What you're not taking into account is that WHOM is just far enough north to be a class C facility, not a class B facility. Class C stations can run 100 kw at up to 600 meters AAT. As Doug's list points out, if WHOM were a height-derated "textbook" C instead of a superpower, it would have 27,652 watts instead of 48,000 watts, which is, as he correctly notes, just a 2.4 dB improvement. (WPKQ is pretty much a textbook C, at 22 kW/1181 m, and its coverage is pretty comparable to WHOM's, except in its directional nulls.)
If WHOM were nominally a B, like most of the signals with which it's compared to the south, it would appear far higher on the list. Without doing the math, I think it would fall in the 15-16 dB range.
It's true that if the formulas for calculating height above average terrain figured in distances out to the edges of the signal's contour - and thus better reflected the huge drop from Mount Washington's peak (some 2000 meters) down to sea level - WHOM would rate higher on the list. But keep in mind that the LA stations at the top of the list would also rate higher if a more "real-life" HAAT formula were used. Mount Wilson is almost as high as Mount Washington - 5700' versus 6200' - and the falloff to sea level is even more dramatic (well under 50 miles to the nearest coastal points.) The Wilson stations benefit from the fact that there are many peaks much taller than Wilson in unpopulated areas to the north that are close enough to figure into the HAAT calculations. If those were taken out of the picture, the Wilson stations would show HAATs of over 2000 meters, rather than 850-1000 meters.
The other thing that makes Doug's figures for the Wilson stations even more dramatic is that those are all nominally class B stations, limited in theory to 50 kW at just 492 meters but actually running as much as 110 kW/863 m. If those stations were in class C territory, only a handful would even be considered superpower. For comparison, a typical Denver class C FM at Lookout Mountain - we'll use KRFX 103.5 - is 100 kW at 300 meters HAAT. In reality, KRFX's antenna is more than 600 meters above downtown Denver and most of the market's population, but the much taller peaks to the west in the Front Range skew the HAAT calculation considerably, to the extent that the Lookout FMs don't even meet the minimum 450 meter HAAT to retain full class C status and face a forced downgrade to C0, receiving slightly less interference protection and allowing several new channels to be squeezed in in outlying areas. For many years, the FCC recognized the unusual terrain around Denver and issued "Denver waivers" that allowed those stations to continue to receive full C protection, but that practice has been challenged and is unlikely to survive.
Another way to look at all of this is the total amount of population covered by a superpowered signal. By that measurement, even given the amount of signal wasted at sea, the Wilson FMs win, hands-down. WHOM may be huge, but it covers an awful lot of places where there aren't very many people.
Still another way to look at all of this is the total land area covered by a station's signal. My recollection is that the list, if ordered that way, would indeed put WHOM at the top, since that measurement would take into account the actual height of Mount Washington above sea level. (The Mount Wilson FMs and 103.3 in Santa Barbara still do well, but not as well, since so much signal - especially Santa Barbara's - is wasted over water.)<P ID="signature">______________
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