This amplifier for instrumentation with very high input impedance was found in a manual of JFET circuits. The operational ones used are current and the power supply must be symmetrical.
We found this circuit in a documentation for 1977 American radio amateurs. The LM336 integrated circuit...
The frequency of this oscillator depends on the coil and the 10 nF capacitor. The circuit is from...
This circuit can work with the previous one generating signals, that can be decoded by it. The...