>or have phase matched down
>conversion and then mix the signal to get a correlation (and thereby
>pull your extraterrestrial signal out of the noise). PLL LNB's are
>just too expensive for an amateur group to afford, so I'm hoping to
>be able to hack some cheap LNBs to do the job and get us started.

Just a suggestion - I have no experience with doing this - but have a look at
the chips sets used in GPS receivers, especially the correlator control chips
that have up to 12 correlators in them to lock onto the satellites. The two
chipsets I looked at are normally supplied with no code in the micro contained
in the correlator chip. If you get real friendly with a rep, they may donate you
a sample chip.