This amplifier with two FETs in direct coupling (cascode) was found in a 90s Popular Electronics. The MOSFET can be of almost any type like the MPF102.
This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and...
Generating a square signal (50% active cycle), this circuit was found in Siliconix documentation from...
This circuit with TTL compatible output was found in a 1968 US documentation. The circuit is...