This circuit for the 60 kHz range was found in 73 magazine and published in 1995. The circuit uses a ferrite rod. Note the direction of the coil windings.
We found this circuit in the February 1983 issue of Radio Electronics magazine. The 4-digit...
We found this circuit in an old American documentation. It is an electronic rheostat with a...
With this circuit it is possible to trace the characteristic curve of a component using an...