Found on an 80's Elektor, this circuit uses common components, being the diode a general purpose germanium. The coils select the frequency range of the indicator that reaches 60 MHz.
We found this interesting timer circuit or CMOS timer in a 1988 publication. The circuit is still...
This circuit found in Radio Electronics can be used in games to produce a random pulse train. The...
We found this amplifier with high input impedance and low capacitance, using FET, in a...