This circuit allows the detection of RF signals using the lowest range of direct currents of a common multimeter. Equivalent diodes such as 1N34 can be used. The circuit is assembled in a ballpoint tube.
We find this circuit in a documentation for engineers from 1971. The circuit generates rectangular and...
This is an integrated recommended for portable amplifiers, recorders, and battery powered radios. It...
This transistor amplifier from the 1950s had gain of 10. The circuit is from Radio Electronics, from the...