This circuit was obtained in a 1967 Electronics World. The components are still common today, the SCRs can be replaced by equivalents and the unijunction transistors the 2N2646.
This circuit appeared in a noverber 1962s Practical Electronics. The magazine is no more, but the...
This circuit is from an American 80's documentation. The integrated circuit is from the time and...
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...