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Author Topic: AM broadcast band plans (Question)  (Read 108 times)

Offline IZS4

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AM broadcast band plans (Question)
« on: May 15, 2019, 1640 UTC »
I have noticed that when im tuning through the AM broadcast bands that there seems to be a lot of broadcast activity outside of the frequencies. For example I thought that 49 meters ended at 6.200 mhz, but there are plenty of stations beyond this. I have noticed this on other bands as well. Maybe I have outdated band plan information? Any insight would be helpful. Thanks

Offline IZS4

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Re: AM broadcast band plans (Question)
« Reply #1 on: May 15, 2019, 1851 UTC »
Hope he doesn't mind. Im going to copy/paste reply from Josh. Thanks again for your response!

This has been going on a long time now, and seems to take place on every band. I suppose what is happening in some cases is the gov officials/engineers who supervise the broadcasts decide for themselves to move out of band so they have a clear channel so to speak. These same guys are also often the reason a station is 10kHz wide or more instead of 6kHz like they should for hfbc

Since hfbc is on a 5kHz slot, modulation splash is often a problem between adjacent broadcasts, as well as having the stronger of two nearby signals grabbing and holding the agc level of a given receiver, reducing the audio power of the lower signal strength sig.

Also consider if the broadcaster has had equipment for such and such a frequency for a long time and then the itu moves the band so their equipment is now out of band, instead of a possibly costly retuning they they say screw it and continue using the freq.

Then there's countries that do as they please, China, North Korea, Iran, etc that take a dim view of itu regulations even while members of itu and fire up jammers and broadcasts wherever they please.

It's not like the itu or un will do anything.

Just some thoughts on an interesting subject, thanks for the question.