Suggested by a 1965 Electronic Design, this circuit has a gain of 15 dB at 45 MHz and can be changed to operate on other frequencies. The tetrode FET is an uncommon component today.
The division by eight using the 4018 is made as shown here. It isn't necessary to use additional...
This simple alarm with latching uses a relay as the main element. The circuit is from a Radio...
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...