modulation is the information impressed upon the carrier. without modulation all you would hear is silence or a quiet spot in the static on the dial.FM and AM are the two kinds of modulation used in Broadcasting.
But i just don't get it, why is Modulation so important in Broadcasting.
Can't a station be broadcast without doing any modulation??
Why is it so important and is it done in Digital Broadcasting???
I agree. The problem is that the name CW, meaning continuous wave (or carrier), is not morse code, which has to turn the carrier on and off at a timed rate to send any useful information. So CW is a misnomer and assumes you understand that the carrier wave is going to be turned on and off to covey the message. In fact when the sender has no information to send he doesn't keep the key down to continue sending a carrier wave, he leaves the key up resulting in on carrier being transmitted. I would have called it KW (keyed wave) rather then CW.Even at 40 wpm, morse code would equate to information at about 3-5 Hz. This would make a pretty narrow peak on a spectrum analyzer. So a narrow peak would not necessarily mean it's not modulated.
Suppose you put old-style teletype on a carrier, instead of morse code? That would be about 110 Hz. Would that be considered modulation?
If you had a micro-controller keying a transmitter at 9600 baud (like I first did with a Z80 in about 1980-something), is that modulation?
I can't help but think CW is a misnomer. Digital, 100% modulation at less than audio frequencies is still modulation. Lots of things don't exactly mean what they are named.
I can still copy 45 words a minute.I guess I'm part of the dying breed of Morse Code Geeks. (Geez! I'm dying? I guess if Papa says so........)
Continuous Wave (A1A)
Radio communication at its most basic (and some say its most fun) level.
It takes effort.
It takes "want to".
Oh yeah, it also takes a radio.
But, thats about all it takes.
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Yes you can. You have two problems though.Can't a station be broadcast without doing any modulation?
Correct, otherwise there wouldn't be any information contained in the carrier and yes it is a misnomer. In fact in modern terminology the name is amplitude-shift-keying (ASK) with 2 amplitude levels. ASK is also used in 8VSB modulation (used in ATSC). The difference is that 8VSB uses 8 amplitude levels instead of 2 and only part of one sideband.Even at 40 wpm, morse code would equate to information at about 3-5 Hz. This would make a pretty narrow peak on a spectrum analyzer. So a narrow peak would not necessarily mean it's not modulated. Suppose you put old-style teletype on a carrier, instead of morse code? That would be about 110 Hz. Would that be considered modulation? ...........
by Jake Hertz
by Duane Benson
by Duane Benson