This broadband amplifier was found in an Elektor from the 90's. The gain is 10 dB with a noise figure of less than 5 dB.
This simple electroscope with bipolar transistors is not the most sensitive, but can detect static...
This oscillator for various frequencies was obtained from a 1980s telecom documentation. The...
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...