Triple-synchronous AM experiment to begin in Kansas City

Triple-synchronous AM experiment to begin in Kansas City

Post by Mark Rober » Sat, 02 Oct 1993 12:01:42

Bill:
    I'm having to mail this directly to you again--more newsreader
trouble, this time on another system that doesn't like uunet
addresses.  At least tyrell's mailer had the decency to tell me
what had happened.  Anyway,  here it is (revised slightly
so the dates make more sense.  -- Mark
-----
    The following are excerpts from an article in the Kansas City
Star business section, "Radio revamp:  triple-synchronous
broadcasting to be tried to extend KNHN's range," Sunday, Sept. 26.
 ***
    William R. Johnson has placed a $300,000 bet with his radio
station.
    The 42-year-old general manager of KNHN-AM is *** that
by using fiber optics, a satellite and special radio crystals he can
simultaneously broadcast from three widely spaced transmission towers
in Kansas City, Kansas; Amoret, Missouri; and Pittsburg, Kansas.
    The new setup is called triple-synchronous broadcasting.  If it
works, it will boost the KNHN signal from 25 miles to about 200 miles,
and Johnson will have created a superstation that can be heard as
far away as the Oklahoma border.
 ***
    The outcome of the gamble, the first time triple-synchronous
broadcasting has been tried in the United States, will be tried in
the United States, will be known when he flips the switch Thursday [Sept. 30].
It has captured the attention of trade magazines and the AM branch
of the Federal Communications Commission, which has granted the
station a two-year experimental license.
    "I will be either a hero or a goat," Johnson said.
 ***
    The station, one of the oldest in the Kansas City area, was
licensed in 1925 and follows the same restrictions today that were imposed
at the time of its licensing.
    "The problem we have is that the station just was not reaching the
suburban areas of Kansas City," Johnson said.  "When you get to southern
Johnson County [Kansas--KC's wealthy suburbs], the signal begins to
deteriorate rapidly."
    Another problem came from radio stations outside the area that were
broadcasting on the same frequency.  Johnson said the KNHN signal,
especially at night, would be hampered by interference from stations
in Pittsburg; Mexico, Missouri; and Springfield [Missouri].
 ***
    About 1-1/2 years ago, he came up with the idea of buying KSEK in
Pittsburg, about 130 miles south of Kansas City.  It broadcast on the
same frequency as KNHN, and the station is now operating under the
call letter of KPHN.
    Early on, Johnson flirted with the possibility of buying the
station solely for the purpose of shutting it down.  But then he realized
that it was a valuable resource and decided to seek ways to synchronize
the signal with KNHN.  To do that, he would have to build a synchronous
tower in Amoret, between Kansas City and Pittsburg.
  ***
    "What they are trying is completely unique to the United States," said
Jim Burtle, who oversees the AM band for the FCC.  "While there are
about a half dozen synchronous stations in operation now, no one has
tried synchronizing three stations before." . . . On Jan. 26, as part of
FCC efforts to improve the AM band, the commission gave KNHN experimental
authorization.
  ***
    Burtle said the FCC would study the test results gathered by KNHN
to establish future regulations on such synchronous operations.
  ***
    Tim Sawyer, owner and technical consultant with T.Z. Sawyer Technical
Consultants, said that although the concept was not new, the technology
had just become available to make it easier to synchronize three stations.
    The key components of KNHN's system ae custom-built crystal
oscillators, which set the frequency of the transmissions.  The crystal
oscillators, about the size of a fist, have been built to be as
accurate as one-tenth of a hertz.  Most radio crystals are accurate
up to 20 hertz.
    Sawyer said that although the coverage would extend to the Oklahoma
border, there would be two two-mile areas where the signals would interfere
with one another, creating loud static.
    Those areas will be about 60 and 100 miles south of Kansas City,
Sawyer said.  Both of these areas are not now served by KNHN.
<end of article>
********
KNHN is a news/talk station at 1340 kHz.  It is one of three news/talk
stations in Kansas City.  During off-peak hours, it rebroadcasts
CNN Headline News.
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Development Center Analyst, Hallmark Cards, Inc., Kansas City, MO
Hallmark isn't on the Internet, so I have nothing to disclaim.
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