This circuit triggers an LED when the input signal exceeds the peak, or the value set in RV1. The transistors can be the modern equivalents BC549.
This frequency band below 15 kHz converter was found in a Popular Electronics from the 90's. The...
The circuit presented is a 10 MHz oscillator with crystal, which already has several splitters for...
We found this circuit in the November 1992 issue of Radio Electronics magazine. The circuit has...