This OF-1 LO oscillator was found in a 1980s American documentation. The transistor can be any general-purpose and C1 / C2 are determined by the frequency.
This circuit has the intensity of the signals controlled by the light that falls on the sensor....
The purpose of the diode in this oscillator circuit is to limit the amplitude of the output...
We found this ladder-shaped signal generator circuit in Radio Electronics magazine from August 1966....