[BC] KOMO Towers

[PeterH]

On Nov 16, 2010, at 12:43 PM, wcj9996 wrote:

> Regarding the KOMO, Seattle directional antenna.  The antenna  
> reference
> point is midway between the end towers.  The antenna is a three tower
> "dog leg" array, which means that that the center tower is offset 10.5
> degrees from the reference point so that the pattern is asymmetrical
> around the line between the end towers.  In this case it provides two
> minima  on the East side and a single broad minima on the West side.

Three in-line towers with the center tower being offset from the true  
origin by as much as 10 degrees is a common method of achieving null- 
filling, which is what is being accomplished with the KOMO array.

Remember, KOMO, then as KJR, was one of the eight de-facto Class I-As  
which were assigned to Region 5 by the 1928 "Band Plan".

1000, then on 970, was assigned on an internationally-cleared basis,  
to the State of Washington in general, and to the City of Seattle in  
particular.

Then, all such de-facto Class I-As were 10 kW, maximum, although a  
number had been authorized at 50 kW, but a few remained at 10 kW  
nights until the 1950s.

The owners of KOMO and KJR did a frequency swap with KJR taking what  
was, then, 920 and KOMO taking what was, then, 970. These later  
became 950 and 1000, respectively.

Subsequently, political pressure resulted in 970, reallocated to 1000  
under NARBA, being broken down with KOMO directionalizing to protect  
WCFL, but, also, a Mexican Class I-B priority was added. KOMO does  
not protect Mexico, but Mexico does not protect either U.S. Class I,  
except as provided by its much lower night power.

So, pre-breakdown, KOMO/KJR was ND-U, and there was no Mexican, and  
no full-time operation of WCFL.