CLIQUE NA IMAGEM E FAÇA PASSO A PASSO UM PROGRAMADOR PIC
Part Total Qty. Description Substitutions
C1 1 Tuning Capacitor (See Notes)
D1 1 1N34 Germanium Diode
L1 1 Loopstick Antenna (See Notes)
SPKR1 1 Crystal Earphone
MISC 1 Wire, Board, Wire For Antenna, Knob For C1
C1 and L1 can be bought, or salvaged from an old AM radio (which is where I got mine). You may need to experiment with the connections on L1 in order to get the best (or any) signal.
You may or may not need the ground connection. I never use it and the radio usually works fine without it.
The bigger the antenna, the more stations you pick up and the louder you hear them. On my radio, I get about 10 stations, 3 of which are very loud in the earphone. Of course, not everyone has room for a 60′ antenna…
A 47K resistor in parallel with the earphone will help properly load the detect