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 circuit in a 1989 publication. Its purpose is to produce noise in the VHF or UHF...
This circuit was found on a Radio Electronics of July 1984. It consists of a source with the 741...
This digital instrument input circuit was found in the September 1989 issue of Radio Electronics...