help with circuit design(bainter notch)

[huricaine]

Chemelec, any notch circuit I have tried none of them are exactly at desired notch so I always look for the frequency with the lowest amplitude. In the case of this bainter circuit I made it was literally 51.4hz

 

[huricaine]

I am going to use precision pots instead on this circuit.

 

[atferrari]

Have you tried other notch filters?

There are many around. Twin T worked for me. Look for Boctor and one like Fleiger or something like that

 

[chemelec]

The Problem is Most Capacitors are +/- 5% or 10% tolerance.
I Believe 1% ones are Available.
Also Polystyrene Caps are Best, But Quite Expensive.
(I have a few values in a 2.5% tolerance.)

Ideally you check a Bunch of Caps and Select Two that are Identical Capacitance and the Exact value you need.

And Resistors are 5% or 1%, Although 0.1% resistors are Available

10 or 25 turn Trim pots are OK, But you should use it in Parallel with a Over Resistance Value, Fixed Resistor.
Than use the trim pot to create the Correct Parallel Resistance.
This is MORE STABLE than just the Trim Pot.