[BC] Class "D" AM Towers

[Dave Hultsman]

In a message dated 2/16/2010 12:13:55 AM Central Standard Time, peterh5322 at rattlebrain.com writes:
>225 degrees on both 650 and 1170 were complete and utter failures. 
>Both of these Blaw-Knox radiators were amputated towards a more 
>forgiving effective height, about 195 degrees in WSM's case. WCAU's 
>radiator no longer stands, but it is understood that the height was 
>similarly reduced.
The WSM, 650 kcps.  tower originally had a taller mast.  Jack DeWitt,  Chief Engineer and later President of WSM, flew around the antenna at different altitudes and distances to find where the high-angle radiation was located.  He used the old field set, which was not considered portable, with two 6 volt car batteries.  After making an analysis of the measurements, he and his consultants agreed to remove the top part of the mast to reduce the electrical height of the tower.
 
The old story I have heard from two older engineers at WSM, that the mast was the flagpole of the elementary school which was right across the street.  The school has since been moved for widening of the road and the flagpole is probably gone away.
 
WLAC on 1510 kcps, has a ND daytime tall tower which in the fall of the year can present some skyway beating of their ground wave signal in the Cool Springs area south of Nashville in that time just before pattern change. I have heard it many times before while driving in and thru the Nashville area. 
 
Dave Hultsman