[time-nuts] AM Broadcast Stations As Frequency Reference...
Burt I. Weiner
biwa at att.net
Fri Oct 14 10:03:31 EDT 2011
The three I mentioned: KFWB 980, KNX 1070, and KDIS 1110 are usually
well within 1 mHz when operating on their GPS referenced
exciters. Do not be fooled by thinking that just because a station
is operating in the IBOC digital mode that they will be GPS
referenced. As I mentioned before, not all stations bother to
install the GPS antenna and some have the antenna connected but have
not enabled the GPS - Don't ask me why. I have also found some
exciters that claim they have satellites but for one reason or
another they did not lock.
> >Curious if anyone knows of central or eastern US stations that would
> >be gps locked.
>I believe the following are:
>710 WOR New York
>810 WGY Schenectady*
>860 CJBC Toronto*
>880 WCBS New York
>960 WELI New Haven
>1000 WMVP Chicago*
>1030 WBZ Boston
>1060 KYW Philadelphia*
>1140 WRVA Richmond*
>1180 WHAM Rochester
>Note that the synthesizer used to generate the carrier from the GPS
>source may not have a resolution of exactly 1.000000 Hz, so some of
>the GPS-locked stations are off nominal by one or two tenths of a
>Hz. The stations with asterisks above are examples. Also, note that
>atmospheric effects phase-modulate the skywave path, so expect as
>much as +/- 0.5 Hz wander (usually less) on DX carriers at
>night. Finally, the stations will not always be running with GPS
>discipline (during maintenance, failures, etc.).
Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California U.S.A.
biwa at att.net
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