And, on the one hand, it's frustrating being the orphan child of the RF
user community: you can't get off the shelf test equipment. On the other
hand, it's cool, because then you have to *build* your test equipment.
Hmm. Should do more of that.
Well, one *does* have to convince someone to pay you to do it..
To the Ku-band downconverters.. They're pretty crummy (but have a decent
SNR to work with).. however, I've seen that there are two kinds.. a
vanilla LNB and ones described as "crystal locked"... both are cheap
($20-30 for the former, maybe twice that for the latter)... what's the
difference? And, getting into time-nuts territory here, where's the
reference for the "locked" variety coming from? Up the coax? inside the
LNB? And, can it be retrofitted from a much quieter oscillator? I was
thinking that one could build a radio camera with a small array of
Ku-band dishes, if you could lock all the receivers together. They *are*
pretty low noise (20-30K)
The key seek-term to add is "external reference" and it seems that 10
MHz sine seems to be the standard external reference frequency for LNBs
with external reference. I know it will be a tricky frequency for you to
score, but the things you do for science.
Browsing the aisles of the local electronics mega-mart... I don't think
I've ever seen "external reference" in the commodity units. I figure
that the "crystal locked" units have a crystal in the LNB (as opposed to
just running the DRO open loop)..
But, presumably, one could modify the LNB to drive the reference with
something external (and somehow, I doubt it will be 10 MHz.. but anyone
able to modify LNBs will be able to make whatever is needed)
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