correct values

[radium98]

Hello folks .
wich are the correct values for the rds filter LC .
after online formula all wrongs .

[Albert H]

I make it about 350µH to get 57kHz with a 22n capacitor.

My filter uses a 1mH inductor in parallel with a 6n8 and a 1n capacitor which comes out very close to 57kHz.

[radium98]

@Albert H , thanks for thoses replies , but 1mH with 6n8 give me 61.033 khz , it is a pass band filter , wich online calculator , you used .

[Albert H]

I didn't. I used

Res Formula.jpg

where F is frequency in Hz, 2pi is 6.283, L is inductance in Henries, and C is capacitance in Farads

You missed the 1n in parallel with the 6n8, which gives you 7n8. So the tuned circuit is (effectively) 1mH in parallel with 7.8nF. With these values, the resonant frequency works out at 56.987 kHz, which is certainly close enough to 57 kHz!

[Albert H]

Like this:

Res Circuit 57kHz.jpg

[radium98]

Thanks a lot Albert H