This low frequency divider uses unijunction transistors. The bipolar transistor can be a BC548 and the zener diode Z4XL can be a 12 V zener. The circuit was found in a 1967 publication.
This simple motor control for alternating current with triac was obtained in a European...
Of course, with a change in the cable length, the frequency can be changed as long as it is within...
This is the receiver circuit for the CB13978B, found in the same 1977 Elettronica Prática...