Can be used as a shield, this old American documentation circuit offers digitally selected attenuation values from 1 to 0.0001. The component used is uncommon today.
This circuit was found in a 1992 Electronics Hobbyst Handbook. The circuit is for the 110 V power...
The Variable Frequency Oscillator (VFO) shown in the figure can generate signals in a frequency...
Available in Mouser Electronics...