Found on 80's Popular Electronics this circuit operates at 455 kHz. The explorer coil is formed by 10 turns of yarn 26 in a 4 inch shape. The indicator is a microammeter.
This circuit consists of a voltage regulator for 6 V batteries with a very low voltage drop. The...
This BFO or OFB for listening to SSB (Single Sideband) signals was found in the January 1996 issue...
We found this circuit in a European publication from the 1990s. Transistors are still common types...