This bench circuit was found in Radio Electronics magazine from December 1957. The circuit generates signals in bands that depend on the coils.
We found this high gain circuit with the LM381 preamplifier in a Radio Electronics from February 1990....
This circuit provides a good audio power from a signal at least 1 V of amplitude. The MOSFET must...
Using a CA3130, operational amplifier with FET, we found this circuit in a 1977 publication. The...