Shortwave Crystal Radio |
The circuit was 'breadboarded' on an old fan regulator baseplate with the coil wound on a white plastic pill bottle.
Shortwave Crystal Radio - Schematic |
Using a 60' wire antenna and earth resulted in 'local strong medium wave station breakthrough' and hum.
With earth disconnected, the breakthrough and hum reduced considerably and it was possible to tune-in to a faint shortwave broadcast. It was from AIR Chennai, on 7380 kHz, located 270 km away.
Tuning further up, a weaker Oriental station was heard.
Severe fading was experienced with both the signals.
Similar results were obtained using a 1.5 m long telescopic antenna and earth.
On a later occasion the same stations came in louder, with no breakthrough and hum, using a 20 m inverted 'V' antenna.
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