[amsat-bb] Doppler shift question

Dave Webb KB1PVH kb1pvh at gmail.com
Thu Jun 6 13:51:23 UTC 2019

I'm pretty sure the reasons for AM in aviation was because equipment was
cheap and easy to build when the aviation band was formed and if 2 stations
doubled they would both be heard.

 My guess for not not having perceived doppler in aviation is because
aircraft aren't flying at 17,500mph and they are using VHF frequencies.
Feel free to contact me if I'm wrong.


Sent from my Galaxy S9

On Thu, Jun 6, 2019, 8:44 AM KC9SGV via AMSAT-BB <amsat-bb at amsat.org> wrote:

> More train Doppler effect.
> These are sound waves, but the RF FM principle is the same.
> Not sure why they don't use AM in space, like in aviation...I.e. NO
> Doppler effect.
> https://youtu.be/fWX38qjECyE
> Sent from my iPad

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