[BC] Franklin Antenna - KTTO (ex-KREM)

[Peter]

On Sep 12, 2008, at 2:53 PM, ACN wrote:

> You need to look up Franklin Antennas on the web.    KFBK in  
> Sacramento =
> still uses a true Franklin.   They are too expensive to build or =
> maintain today.
>

Most bang for the buck, especially at higher frequencies.

WHO found that its Franklin-type (180 over 120) was sufficiently good  
that it rebuilt it in-kind. Same with KSTP, WOC and what was WKY.

(WOAI didn't come to the same conclusions, and after having two 120  
over 120s in two sites, it built its third, and present site as a  
195. As many may know, for a ND-U Class A, 195 is the ideal height  
over any non-sectional, and strangely enough, 195 is the average  
height over all ND-U Class As in the U.S. It is also the CBS de-facto  
standard).

Franklins are NOT de-facto too expensive to maintain. They are  
complicated, however, and must be viewed as such.

In the specific case of KSTP, they are getting the equivalent of 99  
kW input with only 50 kW input, and that alone should be reason enough.

KFBK's are the only true Franklins which still exist in the U.S. I am  
unaware if there were other true Franklins, but at least the FCC was  
good enough to codify a true Franklin by assigning it its own Sect  
code (3). WHO has its own Sect code, too, as does WCCO, but WCCO's  
was never built to my knowledge.


> I don't know if is was designed by a person named Franklin.

Franklin was the family name of the man who patented this kind of  
radiator. It is a British patent.


>
> A true Franklin, has three equal sections.   They are tuned and work =
> together to give the station a greater efficiency that with a non =
> Franklin.

A true Franklin has two equal sections, each of which are 180 degrees.

This is the only type of radiator which the FCC will license as a  
Franklin (Sect 3).

Any other will be licensed as a common sectional (Sect 2).

A 120 over 120 actually produces lower close-in fading than does a  
180 over 180 or a 180 over 120, but this could only recently be  
proved, by use of NEC2.


I reread the KREM documents in their entirety.

The reason the efficiency was so low, relative to a Franklin, is the  
licensee was forced to lower the radiator's efficiency by reason of  
its proximity to the FCC monitoring station.

Others, including KEX, have been forced to make equivalent  
compromises in their arrays also on account of proximity.