"R J Carpenter" wrote in message ...
All of my older FM tuners have a three-gang "bread slicer", A.K.A. variable
capacitor. It tunes (1) the LO, (2) mixer input, (3) RF stage input. Since
the OP wasn't interested in a synthesized LO, a multigang capacitor would
seem to make sense.
With some imagination, one could arrange a scheme so that the LO would lock
to
a synthesized signal every 200 kHz step. Thus one-knob tuning of multiple
stages, yet with synthesizer stability. Details are left as a student
exercise.
73 de bob w3otc
You'd also probably get higher Q with air var. cap.
But everything else is more complicated with this approach
SioL
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