This sensitive circuit was found in the June 1995 Electronics Now magazine. R1 can be from 10k to 1M depending on the desired sensitivity. Power is supplied by the relay.
Found in a QST from the 90's this circuit is suitable for the medium and short-wave range. |...
The circuit shown in figure 1 consists of an Inverter Module for CCFL Lamp that can be supplied with...
This circuit is based on the voltage reference that is uncommon today MC1403. Equivalents can be...