We found this circuit in an Australian publication from 1991. It is a kit of the time with input for a guitar pickup. The range is a few tens of meters.
This circuit uses only passive components calculated for the desired frequency. We found it in an...
This unijunction relaxation oscillator can be used as a very useful signal injector. The circuit is...
Found in a 1965 Electronic Design, this circuit divides the frequency of a 50 MHz signal by 2. The...