Thread: DRM in USA
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Old May 23rd 04, 06:10 AM
Telamon
 
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In article ,
"Brenda Ann Dyer" wrote:

"hwh" wrote in message
...

"Frank Dresser" schreef in bericht
...
Chicago's WIND is a curious case. They went to IBOC a couple of months

ago.
I'd think a station like WIND would be just about the last station to

adopt
IBOC, because it's at the low end of the dial - 560 kHz, and uses a
directional antenna to broadcast from Northwestern Indiana to Chicago.
Getting the necessary 45 kHz bandwidth on a directional antenna at the

low
end of the dial seems to be an engineering worst case scenerio.


I understood this has something to do with the Q-factor of the aerial, is
that correct?
You actually need a bad aerial for IBOC :-)

gr, hwh



There are ways of broadbanding an AM tower. One way is to add longwire
antennas in parallel to the main tower, stood off by a couple feet or so. I
helped install such a system in Portland, Oregon a few years ago.


What you did in effect with the parallel wires was to increase the
diameter of the tower relative to its length, which will broaden its
response. The towers response curve will have a lower and broader
peak.

--
Telamon
Ventura, California