RF detector circuit using 2N2222 transistors
This electronic rf detector circuit project is designed using common transistors and other few common electronic parts. This rf detector circuit responds to RF signals bellow the standard broadcast band to well over 500 MHz and provides an visual , and audible indication when the signal is received.
By adjusting the bias of D2 with the R2 potentiometer the circuit can detect low power or strong signals .
The circuit can be powered using a simple 9 volts battery or any other 9 volts DC power supply circuit . If the rf detector is not enough sensitive you can connect a good wideband RF amp between the antenna and the detector diode .
Keep diode and capacitor (C1) leads short to minimize stray inductance. The used transistors can be : 2N3906 ,2N2907 or other PNP high gain transistor for Q2 and PN2222A , 2N3904 or other NPN high gain transistor for Q1 .