This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power supply and common 100 mA relays.
The XR2206 is not a common component today, but if you have one you can build this function...
This circuit was found in Philips documentation from 1967. The components are of the time, being...
The proposed circuit generates signals in the range between 9 kHz and more than 44 kHz, which, it is...