This circuit, from the 70's, can be assembled with a more modern FET like the BF245. The circuit is powered by a 9 V battery, as its consumption is very low.
This circuit for monitoring telegraphy transmissions was found in a 1975 CQ magazine. Transistors may be...
The integrated circuit used in this application is like the 555. The components depend on the...
The circuit presented is a simple MW tuner that can be plugged into the input of any audio...