dya@unc-c.UUCP (01/10/84)
While we are on the analog subject, does anyone, anywhere, have one
iota of an idea of how one goes about determining the phase response of
a frequency modulation exciter ? No, I don't mean taking a modulation
monitor and running it into a phase meter with the original signal.
I am working on phase-linear stereo generators; etc (it can be done)
and want to determine the effects that the actual FM process has on the
phase coherency of the recovered signal. It is obvious that many methods
of direct FM do not possess anything close to phase linearity. Not counting
the effects of driver and final PA "Q"; transmitting antenna "Q"; and so
on.
Textbooks or an actual method would be greatly appreciated (pointers
to, not the actual textbook....). I have a reasonably complete set of
test equipment for the task, including a tempermental Tek 491 spectrum
analyser. The method should, ideally, be correctable for the phase
anomalies in all the other equipment.
....If phase linearity in audio is anything like the improvement that
SAW filters are for satellite TV and differential gain/differential phase
in the chrominance channel; we may hear accurate FM broadcasts yet.
Thanks..
--David {decvax}!duke!mcnc!unc-c!urp!dya