This circuit was found in the February 1993 issue of Radio Electronics magazine. Some components depend on the crystal frequency and can be changed.
This JFET amplifier was found in documentation from 1958. The circuit has voltage gain of 4 and 10...
This circuit was found in a 1969 Mullard documentation. Used transistors can be replaced with...
In the figure we have a high input impedance stage with a general purpose PNP transistor. An NPN transistor...