Real Bode plot. I have called it staircase for the GOLDEN SUN!
You should get like this with signal generator sweep via o.scope. All this work perfect with only one uA741. I have no money to buy expensive super-puper OPA!
The frontend have:
1 Ferrite antenna
3 Important rewsistors
2 Important capacitors and
1 bipolar supply.
Other resistors and caps are for decoupling. Work with several Li-Ion 18650 or 18630 Chinese batteries.
Thats's all
Regards