This circuit for the 1750 m band was published in the September 1989 Radio Electronics magazine. The range depends on the antenna system and receiver used.
This low drift or offset circuit is from an 80's documentation. The configuration can be made with...
This circuit has a logarithmic response as a function of the light falling on the sensor. The...
Found in 80's Electronic Engineering, this circuit can tune the frequency to be rejected. The power...