Degen DE31 'portable' Shortwave "Active" Loop Antenna
More thoughts on the placement of the variable capacitor
- A parallel resonant circuit has fairly large currents sloshing back
in forth between the caps and the inductor. Of course in a loop
antenna arrangement where we are dealing with microvolts the currents
aren't so large, but, any resistance in the path (such as a long thin
cable) between the inductor loop and the variable capacitor will reduce
the circuit's Q. So an arrangement using a potentiometer by the user
and a varactor diode by the loop end is perfect.
Regards,
Yzordderrex
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