This 80's Exar circuit has a carrier detector for frequencies up to 500 kHz. The circuit uses a company 567 which is still a common component.
We found this antenna amplifier or Booster circuit in an Electronics Now from the 90s. The circuit...
We found this circuit in the Linear Applications Handbook of the 1994 National Semiconductor. The...
This circuit is from a 1976 Motorola power semiconductor manual. In it we have the optical...