Project: 137 MHz Filter for Weather FAX RX
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The weather FAX NOAA satellites transmit around 137 MHz. Unfortunately the airplane band (airplane to tower communication) and also the amateur radio 2 m band is close to this. Further the NOAA satellite signals can be very weak.
To
filter the 137 MHz signal, a narrow SAW filter with a 20 dB
amplifier was necessary:
Built
into a metal case with N-connectors:
Amplification
and band width test with a spectrum analyzer. The mid frequency is
at 137.5 MHz at +/- 1.5 MHz pass band.
