This circuit is from 1969.R1 and R2 are 4.7 M and R3 is 1.2 M. C1 C2 is 22 nF and battery B1 is 300 V. B2 is 1.25 V. The tube is not easy to get these days.
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This circuit is from 1969.R1 and R2 are 4.7 M and R3 is 1.2 M. C1 C2 is 22 nF and battery B1 is 300 V. B2 is 1.25 V. The tube is not easy to get these days.