Found in a publication by Gernsback from 1960, this circuit uses germanium transistors of the time and commercial coils. It can be changed to operate with modern transistors and other wavebands.
This analog thermometer was obtained from an English documentation. The sensor is a common diode...
This circuit is a kind of Hertz Loop that can be used to check the operation of transmitters and...
Two 3-terminal regulators like the LM317 can be used to "clip" a sinusoidal signal, in order to...