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Hybrid tellies · 30th Mar 2010, 8:24 pm

I never did FM theory at coolege. But I think this topic has cleared up a few things for me. With FM the amplitude is constant, deviation is limited to 75Khz, so the modulation frequency varies the carrier so many times +- 75Khz. Ok clear to this point but still not sure what de emphasis is all about and how is the different levels of amplitude or loudness of the modulated signal effect the FM signal. Sorry if this is obvious to some but have never been totally 100% with FM theory.

30th Mar 2010, 8:24 pm	#26
Hybrid tellies Nonode Join Date: Jan 2004 Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area. Posts: 2,965	Re: FM "deviation" I never did FM theory at coolege. But I think this topic has cleared up a few things for me. With FM the amplitude is constant, deviation is limited to 75Khz, so the modulation frequency varies the carrier so many times +- 75Khz. Ok clear to this point but still not sure what de emphasis is all about and how is the different levels of amplitude or loudness of the modulated signal effect the FM signal. Sorry if this is obvious to some but have never been totally 100% with FM theory. __________________ Simon BVWS member