We found this time base of 0.1 to 90 seconds in a circuit manual from the 90s. The single-use transistors used are common and the frequencies given by the adjustment by the potentiometer.
This high impedance and low capacitance buffer employs a junction FET that can be BF245 or...
Found in 1980s documentation, this amplifier uses a symmetric source and the gain is given by the...
This circuit was found in an old documentation for radio amateurs, being indicated for...