Optimal inductance for BWF coil

mdjurfeldt

New member
Hi,

Reading here , it seems like I can use a 104 mH coil together with the LM386 200x amplifier. However, looking at the schematics of that amplifier, there seems to be a 10 uF capacitor at its input. Using the formula f = 1/(Pi*sqrt(LC)), that seems to indicate a need for a 40 uH coil in order to get a resonance frequency of 8 KHz.

Can someone please explain to me why it is better to use the 104 mH coil and how to understand its value?

Best regards,
Mikael
 
Oben