[Lowfer] LOWFER receiver conundrum.

[JD]

>>> I've yet to find anything about using a PLL and reference oscillator to 
>>> generate a frequency *lower* than the reference oscillator.

It's actually a very common thing, Ben.  The reference _oscillator_ is 
seldom used directly on its own as the reference _frequency_  in the phase 
locked loop.  Most often, the crystal or GPS source is divided down to 
whatever step size you want the PLL to be able to tune in multiples of (10 
kHz, 1 kHz, or whatever).

Online, I haven't yet found what I consider to be a really suitable document 
that takes one from beginner to intermediate level with hands-on examples 
all the way.  They all seem to go into way too much detail about one aspect 
or another of the subject, then skip over other rather important points 
between.  Not everything worthwhile is on the Web!  Probably the best route 
is the good old fashioned printed page, and probably the best general 
experimenter's reference book on PLLs is the one by Don Lancaster.

A condensed and somewhat mathematical online tutorial is at Analog Devices:
http://www.analog.com/static/imported-files/tutorials/MT-086.pdf
I mention it because their bibliography lists some really good, if slightly 
more advanced, books on PLL design that you might find helpful if you get 
into the subject seriously.

Good luck.

John