Re: WBZ's new towers

[Dan Strassberg <dan.strassberg@worldnet.att.net>]

At 12:48 PM 6/18/97 +0000, you wrote:
>>>        Does anyone know whether any Class A stations currently use a
>>>Franklin antenna?
>[...]
>>KDKA and WHO, I believe. Also, KSTP uses one during the day but at night
>>operates directionally, from conventional towers, using a different site a
>>few miles from the day site.
>
>KDKA used to run a Franklin antenna, but it was torn down just a few years
>ago in favor of a more "conventional" design on the same site.  I remember
>reading about it in Radio World not that long ago, in an article written
>by KDKA's CE.  If I remember right, he wrote that the new antenna would
>provide a better local signal than the Franklin did; that was at least
>part of the reason why it was replaced.
>
I believe that KDKA did replace the tower; now that you mention it, I think
I read it somewhere else also. However, I think the chief engineer's
statement is baloney--intended to mollify the local listeners. Unless the
Franklin's high field strength was accompanied by a high-angle lobe of the
type produced by 5/8-wavelength towers of conventional design, the
Franklin's higher groundwave field strength--the result of "squashing" the
vertical radiation pattern--should have produced a better local signal. If
there was a high-angle lobe, however, KDKA's skywave could have been
interfering with its groundwave as close as 20 to 30 miles from the TX. I
suspect that the real story is that the tower needed replacement and the
Franklin had always been troublesome. Putting in another Franklin would have
cost too much and the payback would have been negligible, especially in
light of the higher ongoing expense of maintaining the taller tower. So
Westinghouse took the pragmatic approach and installed a tower of
conventional design, realizing that nobody who counts would ever notice the
difference.

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Dan Strassberg (Note: Address is CASE SENSITIVE!)
ALL _LOWER_ CASE!!!--> dan.strassberg@worldnet.att.net
(617) 558-4205; Fax (617) 928-4205

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