This circuit appears elsewhere on this site. The CMOS gate can be any one, including NAND and NOR gates connected as inverters. R1 values are between 1 and 5 MHz and R2 around 10 kHz.
This circuit appears elsewhere on this site. The CMOS gate can be any one, including NAND and NOR gates connected as inverters. R1 values are between 1 and 5 MHz and R2 around 10 kHz.