This circuit was obtained in a 1975 documentation. The maximum frequency depends on the diodes and the FET. Type 1N34 diodes and a FET BF245 can be used for frequencies up to 100 MHz.
This circuit was found in a 1980s documentation. The IC is the 7400 and should be powered with 5...
The function generator XR2206 is not very easy to obtain, but if you get one you can assemble this...
This circuit converts a 12 V continuous voltage from a battery into an alternating voltage of 110...