This circuit can generate signals of different frequencies, switched by a DC voltage. The frequencies are determined by the crystals. The circuit is from a 90s American documentation.
We found this oscillator in a publication for radio amateurs from the 70s. The circuit generates...
We found this circuit in a 1982 publication, but all the components used are still common in our...
We found this circuit in a 1976 technical documentation, but it can be assembled with modern...