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Name: davidjones
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: Around 1993

I am having difficulty understanding how a FM signal is modulated on to a carrier wave. My text book just not seem to explain it to my satisfaction. AM modulation is fairly easy to understand, so maybe we you can relate the two somehow, showing me the similarities and the differences.

AM modulates the AMPLITUDE of a fixed frequency carrier; FM modulates the FREQUENCY of a fixed amplitude carrier. Actually, it does not have to be fixed amplitude: one of the main reasons for developing FM technology was to become immune to amplitude changes; like lightening produces static on AM but not on FM.

jade hawk

Also, there is a satellite now in operation that uses cryogenic cooling. I am not sure what the coolant is, but the satellite parts are cooled down to about 6-12 Kelvin. Pretty cold, eh? I believe it is a NASA satellite aimed at observing different kinds of radiation reaching the Earth from other galaxies/stars, etc. It was in one of the issues of Aviation Week and Space Technology magazine.

wildman jackson

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