We found this circuit in a 1964 Electronic Design. It divides the frequency of a 20 MHz signal by 2. The circuit uses a transistor from that time. Details of the coils were not given.
Using a 4046 PLL, which is not very common nowadays, this circuit was found in the October 1994...
This circuit includes an AD converter for interfacing with a microprocessor and can be used as a...
Found elsewhere in this section, this circuit mimics the noise of a steam locomotive. This was...