Here is one plan as simple as a radio receiver can get. I don't know how good in practice:
Passive Aircraft Receiver
http://www.pcs-electronics.com/schematics/aircraft.pdfThe Passive Aircraft Receiver is basically an amplified "crystal radio" designed to receive AM aircraft transmissions.
The "passive" design uses no oscillators or other RF circuitry capable of interfering with aircraft
communications.
The tuning capacitor may be any small variable with a range from about 5 pF to about 15 or 20 pF. The
0.15 uH inductor may be a molded choke or a few turns wound with a small diameter. Experiment with the
coil to get the desired tuning range. The aircraft frequencies are directly above the FM band so a proper
inductor will tune FM stations with the capacitor set near maximum capacity
Other capacitor and inductor combinations may be selected
to tune other bands if desired. (Try the CB band at 27 MHz.)
The antenna can be a couple of inches if the receiver is near the transmitter or a couple of feet for maximum
range. The selectivity is reduce as the antenna length is increased so best performance is achieved with the
shortest acceptable antenna
Here is one plan as simple as a radio receiver can get. I don't know how good in practice:
Passive Aircraft Receiver
http://www.pcs-electronics.com/schematics/aircraft.pdf
The Passive Aircraft Receiver is basically an amplified "crystal radio" designed to receive AM aircraft transmissions.
The "passive" design uses no oscillators or other RF circuitry capable of interfering with aircraft
communications.
The tuning capacitor may be any small variable with a range from about 5 pF to about 15 or 20 pF. The
0.15 uH inductor may be a molded choke or a few turns wound with a small diameter. Experiment with the
coil to get the desired tuning range. The aircraft frequencies are directly above the FM band so a proper
inductor will tune FM stations with the capacitor set near maximum capacity
Other capacitor and inductor combinations may be selected
to tune other bands if desired. (Try the CB band at 27 MHz.)
The antenna can be a couple of inches if the receiver is near the transmitter or a couple of feet for maximum
range. The selectivity is reduce as the antenna length is increased so best performance is achieved with the
shortest acceptable antenna
