This circuit turns off after a time given by capacitor C1. This component can have from 1 to 1,000 uF depending on the desired time. The circuit is from an Electronics Now from June 1995.
The two circuits shown show how to obtain an SSB / CW control for receiving this signal top at a...
This variable voltage regulator circuit has a power stage capable of supplying currents up to 1 A....
We find this encoding circuit in an American 1980s amateur radio documentation. The circuit can be...