Found in American documentation from the 1980s, this circuit operates in the frequency range 0.5 to 20 MHz. The power can be between 5 and 15 V.
We find this vibrato configuration with transistors in a 1987 documentation. The components are still...
This oscillator with the 4049 can generate signals up to about 14 MHz according to the article in the...
Found in a 90s Popular Electronics, this circuit provides sinusoidal signals at frequencies given by the...