We found this precision circuit in a manual from the 80's. The operational amplifier is of a common type at the time, and equivalents can be tested. Transistors are general purpose types.
The two circuits shown show how to obtain an SSB / CW control for receiving this signal top at a...
The basic application of a 4017 as a sequencer [10 steps] is shown here. In this same part, you...
In the original circuit a 40431 quadrac is used, but this is not a common component today....