This circuit with power MOSFETs was found in a 1980s Siliconix documentation. Equivalent MOSFETs can be used, as well as other transistors. Note the symmetric power supply.
This circuit is from the 1974 Motorola Unijunction Trigger Circuits for Gated Thyristor. The triac...
Found in old American documentation, this circuit can divide the frequency of a signal by 2 or 3...
This transceiver is also low power, but this time, it can generate signals in the 144 MHz band. In the...