Very high microphone gain
History
This
project is my father’s idea, he found in an old army surplus store
with a radar dish and mount. His idea was to make a very high gain
microphone to be able to listen to almost anything, like birds or
whatever else you want. The electronic circuit is simple, just an
electret’s microphone mounted in the focal point of the dish. An
amplifier made of two op-amps, the first to give more gain and the
second and most important is the AGC "Automatic Gain Control." With
the AGC the audio signal you hear weather far or near, will be the
same. In the schematic there is no power output for the audio, you
can use a simple LM386 to drive a head phone. It is incredible what
you can hear with this high gain dish mounted microphone! Have fun.
My father and his dish