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Old August 30th 16, 10:03 PM posted to rec.radio.amateur.antenna
Ralph Mowery Ralph Mowery is offline
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Default ARRL General Class Study Guide

In article , says...

On 8/30/2016 4:01 PM, Ralph Mowery wrote:
In article ,

says...


The 15 kHz spacing comes from years ago. I may be wrong on the spacing
of comercial FM being 60 kHz, but think it was at one time. I know it
was 30 kHz at one time and the deviation was set at 15 kHz. Then as the
bands got more occupied and the stability of the equipment improved the
comercial stuff just went to 5 kHz deviationa and cut the bandwidth in
half to 15 kHz.


I was not aware that FM broadcast radio was ever spaced at 60 kHz. My
understanding is the bandwidth is most of the 200 kHz channel spacing
which is a bit too close to prevent interference on adjacent channels in
many cases. Typically they don't assign adjacent channels in
overlapping areas.


I should have been clearer. I was thinking of the comercial two way
radios like the public service of police and taxi cabss. Not the
FM broadcast stations.

The FM broadcast stations are deviating much wider than the 5 and 15
kHz we were talking about.

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