We found this circuit in a 1965 magazine. The circuit can be assembled with current equivalent transistors and the precision in generating the frequencies depends on the tolerance of the capacitors.
Indicated for scanning circuit applications, we found this generator in a Radio Electronics from the 80s....
The circuit shown in figure 3 uses a programmable unijunction transistor (PUT) of the BRY39 type...
This is the version of the previous circuit with a locking system. The supply voltage is according to...