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Old June 11th 04, 01:53 AM
Sam Byrams
 
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Since the superheterodyne patents either started being licensed at
reasonable rates or ran out, few receivers of any other type have been
built. With very good reason.

PCB construction makes more sense for IF strips than for pure
baseband hardware when tubes are employed, but I don't know that
there's a big advantage to doing it with tubes unless you just like to
work with tubes. Doing it with FETs might make more sense. Still, very
good RF boxes were built before the PCB days.

I think you should get some coil components, which are still
available, and either a noise generator and a spectrum analyzer (or
one with a track gen...) or better yet a network analyzer , which will
show both transmission and reflected paths, and just decide what kind
of "haystack" you want, and cobble to suit. RF software exists so that
you can play with precise parms of I and C, but you will be happier
with the cut and try given stray inductance and capacitance and other
variables at 10.7 MHz (or whatever IF you wind up with.) People once
did it without these tools but then it took prodigal amounts of time
and they had techs and test operators who worked cheap.

When you get done, you will have the best fidelity of current AM
broadcast signals available. However, considering as how they've been
Orbanned into submission for "dial punch", and considering commercial
broadcast at least in the US sucks **** through a straw right now
content-wise, it may be a wholly Pyrrhic victory.