We found this circuit in a 70s Electronic Design documentation. The circuit uses general-purpose transistors from the time. Linearity is better than 0.25%.
An inproved version of the circuit CIR129E is shown here. The resistorR1 must be at least 5 times...
We found this circuit in an old documentation. It can be elaborated based on modern components. The...
In this circuit of a 1956 publication, the handset must be high-impedance magnetic and L1 has 200...