The purpose of this circuit is to measure the resistance of an antenna at the resonant frequency. The circuit is from an old American documentation for hams.
The 4007 integrated circuit consists of 4 MOSFETs that can be used separately. The figure shows how...
August 2016 - It can be obtained from Mouser Electronics new operational amplifiers with extremely low...
This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's...