jmtillery said:
I'm an old guy who has lived through AM's heyday. We always joked about stations back in the day called "paper 50's" and "paper 5's" and so on. In other words, to get the 50,000 watt moniker or the 5,000 watt moniker on station letterhead, consulting engineers designed directional arrays with high losses. If the interference limits only allowed, let say, a 3,000 watt operation, the consultant could arrange and feed the towers in such a way that the interaction between them dissipated the excess RF power in the form of heat and therefore required 5,000 watts of input.
To see the efficiency of a directional, one has to look at the "RMS/RSS" ratio, “IR” losses, the electrical height of the towers, etc. The trade off, is these lossy antenna systems were often unwieldy and troublesome. They required a lot of constant tweaking to keep them working and legal. This got to be such a headache, that the FCC in the late 70’s stop licensing arrays with RMS/RSS ratios over 3 unless you could prove you could make it work and keep it working.
It was a very different world back then. This was done because advertising agencies would look at a station's power and equate it to reach. Ratings were not widely accepted, as methodology was often corrupt, unaccredited and flawed. In those days, one could assume an audience by just being on the air and a bigger audience by being low on the dial with lots of watts. You get the idea.
Also, remember the old power steps: 250, 500, 1000, 5000, 10,000, 25,000 and 50,000 watts back then. Until they added the intermediate step of 2500 watts in the 70’s, many stations were stuck with either with a “creative” array design or just operated with 1,000 watts.
A classic example of an efficient array is WDBO's nighttime. Also, the 1520 daytime in Apopka and the old 1600 day and night in Winter Garden were very efficient, particularly with their half wave or better towers. These arrays actually produce more “power out” than in, or have an ERP gain like an FM.
Examples of "letterheads" are the 950 nighttime, the 1060 nighttime, the old WAPE 690 nighttime, and yes, I'm sorry to say, WELE is a poster child. The day pattern sucked, but the nighttime is very lossy and unstable. It was made much worse when it was bumped up to 2,500 watts. The 1380 contract engineer 20 some-years ago, was my engineer, and boy did he come in my office and tell some stories!
Sorry, Mr. Tillery, WELE plays in spite of itself because most of the population is up and down the coast, i.e. saltwater marsh and hence, high conductivity. One doesn't need much power when you have conductivity. Case in point, 1340 down the street used to easily out play the 1380, both day and night. I'm guessing that this is still the case.
I haven’t looked at WIXC daytime in the FCC database, but given the nighttime, (5 tower in-line; these arrays generally suck as a rule,) it certainly possible to put 50,000 watts in and have bad coverage from the array design. Or, even poor array tune-up can create big problems. Since they are sitting in a swamp, even if most of the ground system is gone, it would make that much difference. Not nearly as much as the array design itself.
Tx
Maybe some of you "Nuts" don't realize it but FSU is in the ACC Conference and was playing in the finals in Atlanta against Duke, I believe..They lost but there was nationwide interest in the game.. Acttually, I hate FSU as I am a Fla Gator Grad circa 1971 but that's the scoop on The game being carried!