This circuit was obtained in an American publication of 1970, making use of components of the time. Components may be replaced by equivalents.
Found in a 1965 General Electric circuit manual, this circuit uses SCRs from that time. Modern...
This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can...
Found in a 1969 Ferranti documentation, this circuit uses only bipolar transistors from that time....