"John Byrns" wrote in message
...
In article , inch (Peter
H.) wrote:
The rf output of 1050 ESPN is directional, favoring the northeast. There is a
null toward Philadephia to protect 1060 KYW.
Actually, it is precisely the opposite.
KYW was moved to Philadelphia from Chicago, probably as a 10 kW-U, ND station.
1060 in Philadelphia would be mutually exclusive with 1050 in New York if KYW
didn't protect 1050, thereby establishing a defendable Class A contour towards
the NE (and 1050) for itself.
This all seems quite strange, so I assume there is a good story to explain
how it all came about? Not knowing the dates when KYW moved to
Philadelphia, or when the "NARBA" was ratified, I assume that the move of
KYW occurred well before the "NARBA"? If this is the case, how did the
KYW pattern come to have such a deep null towards WINS, which wouldn't
have even existed at the time?
As noted earlier, though, KYW has a minima, not a null. I suspect (although I make
no claims to its accuracy) that the protection afforded the southwest (since it's
done with two towers in Whitemarsh, PA, which is to the northeast of City Center)
required that the maxima be directed towards Philadelphia and, serendipitously, in
the other direction towards Reading, Harrisburg and Scranton. As a result of the
minimum towards the southwest, and due to the two-tower design and the need to direct
maximum towards Philadelphia, this resulted in a second minimum in the direction of
New York. It was this protection which was already in place that allowed WHN to get
their pattern and power. So KYW isn't really protecting 1050, and thus a 1-B is
protecting a II...the antenna design simply fails to provide converage in that
direction, but which still required that WHN (or ESPN 1050) protect KYW to the limits
required in the rules.
And WINS (that was a mistake, right?) has nothing to do with this....at 1010, it's
far enough away from 1060 that neither station figures in the pattern of the other.
Also of note is that WBZ has a directional pattern, but as a 1-A it protects nothing.
It's done with a parasitic element suspended from the guy wires, which pulls in the
power which would be wasted over the Atlantic.
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