1510 changes

Dan.Strassberg dan.strassberg@att.net
Sun Apr 6 17:48:24 EDT 2008

No; WWZN's night pattern is asymmetrical; there is a small lobe to the
north and northwest that more-or-less approximates that portion of the
old 5 kW two-tower DA-1 pattern. There is no symmetrical lobe to the
southwest, because such a lobe, if it existed, would be aimed more or
less toward WLAC. Remember, the night array's towers are not in line,
so there is nothing about the array geometry that forces the pattern
to be symmetrical. Indeed, if you draw a line through the east and
west towers, the two towers that do not lie on that axis are not
symmetrically located about it.

Nevertheless, I believe that constraints other than protections to KGA
determined the WWZN array's performance. I suspect that enhancing the
minor lobe to the northwest by even a relatively minor amount would
run afoul of protections to WLAC, whose night pattern sends
appreciable energy to the north. WLAC's skywave in central and western
New York is quite strong and probably interferes noticeably with WWKB
at the fringes of the Buffalo station's groundwave coverage. (Scott?)

Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "Garrett Wollman" <wollman@bimajority.org>
To: "Laurence Glavin" <lglavin@mail.com>
Cc: "Boston Radio Interest"
Sent: Sunday, April 06, 2008 5:28 PM
Subject: 1510 changes

> <<On Sun, 6 Apr 2008 14:55:52 -0500, "Laurence Glavin"
> <lglavin@mail.com> said:
>> BTW, speaking of long-distance AM propagation...  could changes at
>> Spoke-ann's KGA-AM 1510 allow WWZN to loosen up its nighttime
>> signal
>> to NNW.
> I don't think so; the current WWZN array protects KGA mostly as a
> side-effect of the protection it must give to WLAC in Nashville.
> (If
> I remember correctly, the pattern is symmetric about the east-west
> axis, so increasing radiation to the NNW would also increase
> radiation
> to the SSW.  But it's a four-tower rhombus and you can do lots of
> funky stuff with four-tower rhombi.)
> It appears that KGA's application would allow WLAC to increase its
> radiation towards the northwest somewhat, although WLAC is much
> closer
> to its class-A first-adjacents in Minneapolis and Oklahoma City.
> (IIRC, WLAC's array is a bit less flexible.)
> -GAWollman

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