Receiver for the 40m band LM602 (CB25305E)

This circuit uses an FM IF transformer for tuning. The circuit is from a Radio Electronics magazine from April 1990.

Touch Switch or Proximity Sensor (CB5061E)
This circuit is from an 80's documentation, making use of PUTs that are not currently common...
Pulse Logic Test (CB4721E)
This logic level indicator also indicates the presence of pulsating signals through a third LED. It...
Null adjustment shield (CB4902E)
This microcontrolled null adjustment for operational amplifiers was obtained in a Linear...