R1 may be 10k and R2 100k. The transistor can be the BC548 and instead of the small lamp we can use a series LED with a 1k resistor. D1 is germanium and C1 is 10 nF. C2 can be 47 nF.
This 80's circuit has an input resistance of the order of 880 M and gain 10, using operational...
We found this circuit in the Audio Handbook of the National Semiconductor of 1977. The circuit is used...
Published in 1988 in Hands-On Electronics, this circuit converts the 12 V of a battery into 120 V...