Re: Full-Range IF Selectivity; The Hammarlund Variable Crystal Filter
I wanted to simplify the circuit diagram of the filter so I've re-drawn it to British convention and also, I've left out the circuit to switch out the crystal.
Given that the circuit allows a quite wide bandwidth, it seems to me that for a comms Rx, there is no need to switch it out. Leaving out that feature simplifies the construction and will also reduce the capacitance around the crystal. Does that sound sensible?
B
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