This two-transistor circuit is from a December 1964 Radio Electronics. Modern transistors can be tested. The headphone must be high impedance or crystal with a 2k2 resistor in parallel.
This circuit was obtained in an old publication of 1978. The integrated circuit is the critical...
This two-stage amplifier hás a high impedance input and excelent voltage gain. It can be used as a...
This circuit provides a signal of higher frequency the greater the intensity of the light incident on...