Hi Rik, Jim, Rye and all,
The error between input and
output phases could be corrected either by increasing the VCO
frequency until the output phase "catches up" with the input, or
decreasing it until it "slows down" to match the input. The output
phase could shift in either direction, although the end result would
always be to match the input phase.
Like in real life, it's sometimes a sad thing to have to decide one way or
another. If that PLL could take both routes simultaneously, the result would
be perfect soft BPSK again :-) . In the 30's, there was a scheme called
"Chireix modulation" which added the power outputs of two phase-modulated
class-C transmitters to achieve AM in an efficient way.
I am working on this round thing that can be used to reduce friction rather
than simply dragging things across the ground.....
Me too, apparently... I hardly dare say it in public, but in my opinion,
re-inventing basic stuff is not so stupid at all. Don't we learn a lot more
by own thinking and fiddling than by just believing in the solutions the
experts have come up with for us? Trying to catch a glimpse of tiny dots
encircling Jupiter in a homemade cardbord-roll telescope may be more exciting
and instructive than a great show of colourful deep-sky HST images on the
web. Which of course is not bad, either...
73 de Markus, DF6NM
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