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.
This VCO with a common operational amplifier was found in an old American documentation. The...
This regenerative circuit was found in a Japanese publication from the 1960s. Details of the coils...
This experimental monostable CMOS circuit, activating an LED was found in a documentation from the...