This 4-tube circuit was found on a Radio Craft from December 1945. The circuit has excellent sensitivity. Power comes from a power supply with a transformer.
This 100-second timer was found in a 2000 Poptronics. The magazine no longer exists, but the...
The 3-digit AD converter on this circuit is not very common today. It uses 2 integrated circuits to...
We found this circuit in the National Semiconductor FET manual. The components are calculated...