This circuit was found in documentation from the 1970s. The transistor supports modern equivalents. L1 with C4 determines the frequency range of the signals that will be produced.
This circuit, suggested by National Semiconductor, provides an output voltage proportional to the...
Found in 1980s documentation, this amplifier uses a symmetric source and the gain is given by the...
This modulated light transmitter was found in a 90s Popular Electronics. In place of the lamp with...