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Here’s how the spectrum is used in the USA….will try to find Canada’s but I suspect it’s not much different. Don’t know how up to date this is as TV is there.
https://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf
The aviation bands above the FM band still are in analog and use AM transmission
Mark
Total posts : 45366
Total posts : 45366
Total posts : 45366You can also have this sent to you for free as a wall chart.
Total posts : 45366With the way the FAA does things I’d imagine aviation will always be AM, they’re pretty big fans of keeping things around that are proven to work. Does make me wonder what the actual advantage of using AM vs FM on VHF is. The band doesn’t seem noisey at all so I wonder if its an amplification thing for far away traffic. (Assuming AM transmissions are easier to boost on the rcvr side than FM)
Total posts : 45366The reason aviaton uses AM is something to do with the frequency stability when planes are communicating and pass each other at high speed where FM would waver as the planes pass and loose communication for a certain time.
Mark
Total posts : 45366Like AM CB, you can hear if someone is calling in the background, even if they have a much weaker signal. That way if someone has a radio stuck in transmit, it won’t deaden the whole channel. That’s what I was told when younger and pestering an old radioman, and I think he had worked in aviation.
Total posts : 45366By the Spectrum in the United States it’s still showing that 76 – 88 megahertz is channels five and six. We all know that they are not being used. So here in the United States it still looks like 87.1 – 87.9 is Open Season and should be given to have the broadcasters.
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