Re: WOWO

[PeterH5322@aol.com]

In a message dated 1/7/00 11:36:55 AM, ednstrassberg@cahners.com writes:

<<
Now that WOWO has received the license to cover for its downsized 9800W
nighttime operation, the station has filed to increase night power to
15000W. The proposal involves removing the east tower of the present
three-tower night array (same towers that were used for the former 50 kW
night operation) and constructing two new towers well to the south of the
remaining pair. The setup would be close to a parallelogram, but the spacing
between the two new towers would be less than that between the existing
pair. Like the old towers, the new ones would be half wave. Besides
increasing the RMS field from 1144 mV/m to 1503 mV/m, the proposal
significantly alters the night pattern. Instead of having main lobes more of
less to the north and south (as in the present pattern), WOWO's radiation
maxima would be to the northeast and southeast, surrounding a null to the
east to protect WLIB. Coverage of much of the COL would be significantly
improved--perhaps even enough to give WOWO a listenable signal in Fort Wayne
at night once again. The proposed pattern suggests that the new owners of
co-channel WGKA Atlanta (Salem Communications) and possibly the owners of
KOOO Dallas (Infinity/CBS) might be paying for the upgrade. This change
would significantly reduce interference to WGKA, making it much more
practical for the station, which is currently a daytimer, to operate full
time.
>>

It's not too difficult to figure out how this pattern was developed.

It is not a strict "multiplication method" array, but it is almost so.

Tower 2 (old Tower 3) and Tower 3 are spaced 256.4 degrees on a 17.9/197.9
degree bearing. This produces a three leaf cloverleaf with one lobe directed 
at
17.9 degrees.

There are two other lobes and these must be symmetric about a 17.9/197.9
degree axis. Let's say that these lobes are directed at 135.0 degrees and 
260.8
degrees.

Towers 1 (old Tower 1) and Tower 2 (old Tower 3) are spaced 131.0 degrees on a
80.8/260.8 degree bearing. This produces a modified cardioid with the major
lobe directed at 80.8 degrees and a null directed at 260.8 degrees, or a pair 
of
quite closely spaced nulls directed symmetrically about 260.8 degrees.

Because "pattern rotation" will affect the resultant pattern, we would 
certainly
expect the lobe theoretically directed towards 17.9 degrees to be rotated
clockwise and the lobe theoretically directed towards 135.0 degrees to be
rotated counterclockwise.

This appears to be true as the application pattern maxima includes major lobes
directed at 27.7 degrees (a 9.8 degree clockwise rotation from the 
theoretical)
and at 124.9 degrees (a 10.1 degree counterclockwise rotation from the
hypothesized theoretical).

The "back side" lobe which is theoretically directed towards 260.8 degrees is
canceled to a very significant degree by the pattern produced by the Tower
1/Tower 2 and Tower 4/Tower 3 pair.

The most significant nulls in this pattern are directed towards 85.4, 173.0,
240.8 and 319.4 degrees.

The bearings to New York (Class B), Atlanta (Class D, apparently soon to 
become
Class B), Guadalajara (Class A, "grandfathered" at 10 kW ND-N, 50 kW ND-D),
Kansas City (Class B upgrade application submitted years ago, apparently
simultaneously with the WOWO downgrade to Class B) and Portland (Class A, 50
kW DA-N with an application submitted to open up its pattern towards both
WOWO and XEWK) are 92, 173, 213, 255 and 279 degrees, respectively.

There are no nulls directed precisely towards the co-channel Class As (KEX,
XEWK), nor is there a null directed precisely at New York (WLIB), although 
that
minima is close at only 6.6 degrees off theoretical.

The only null which is directed precisely towards a co-channel station is that
directed towards Atlanta, and that null is spot-on.

So, by very strong inference, it is Atlanta that is benefiting the most from 
this
application. Therefore it can reasonably be assumed that Salem is paying for 
all
or most of the changes.

The resulting pattern is quite efficient at 395.12 mV/m/kW at 1 km, or
significantly higher than required for a Class A station.

Too bad now that a greater than 10 kW night pattern is in hand, 
"grandfathered"
Class A status is not possible for the late, great WOWO.

Peter Haas ...
... a relatively warm day in Monterey Bay