This circuit for RF measurements at 200 MHz was found in no documentation two years 80. At a sensitivity of 1V peak and the components used are still common in these days.
This circuit was obtained from a 1962 magazine. It can still be mounted to be powered from 6 V...
This electronic level or plumb indicator has two mercury switches as sensors. The indication is...
This inverting amplifier has a transistor output stage that can increase its current capacity. Higher...