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.

Gate Dipper (CB13563E)
This is a MOSFET version of a grid dip meter for frequencies between 1.8 MHz and 150 MHz,...
Fiber optic receiver (CB9737E)
This circuit has a sensitivity of 2uW. We found it in documentation from the 1980s. The integrated...
Optical Pyrometer LM10 (CB14318E)
The sensors in this circuit are photodiodes with filters. The circuit is suggested by the National...