On 1 Oct 2005 20:54:02 -0700, said in
rec.radio.scanner:

i guess i was trying to find out how many ways signal can be modulated.
even if the signal is digital, isn't it still modulated in fm?

Unless it's modulated in AM, SSB (which is really AM or FM, but we
usually use the term to mean one AM sideband) or some weird modulation
I haven't heard of.

Digital is the format of the data being used to modulate, FM is the
method of modulation.

It's like English/French vs. VHS/Beta. Either language can be put on
either tape format. Any data format (analog, any form of digital) can
be impressed on the amplitude of the carrier (AM), the frequency of
the carrier (FM) or, presumably on some other characteristic of the
carrier, if someone can come up with one.