To reduce interference from man-made noise, I often use a loop antenna which is known for its ability to decrease unwanted signals.
I don't use this antenna to transmit.
Advantage: antenna does not take up extra space.
Disadvantage: antenna is not rotatable.
Keep in mind that there is no metal close to the antenna.
Detail of the Coupling loop:
Detail of the capacitor:
Cmin = 30 pf in parallel with 200 pF = 230 pF ==> Resonance Frequency = 4.050 KHz
Cmax = 150 pf in parallel with 200 pF = 350 pF ==> Resonance Frequency = 3.336 KHz
Calculated L value = 6.5 µH
Measuring results:
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