Signals of up to a few tens of kilohertz can be generated by this circuit found in a European publication from the 1980s. Transistors admit equivalents and the unijunction can be 2N2646.
The coil can be formed by 100 turns of 26 or 28 wire on a ferrite rod in this medium wave radio...
This circuit is from a 1968 Electronic Design. The characteristics of the output transformer are not...
This circuit is from a 1970 publication, having been implemented with germanium PNP transistors. We can...