All Band Converter (T1254E)

This circuit can be used as a band converter or as an input stage for a superheterodyne receiver. The circuit is from a Radio Craft from April 1948.

6 to 60 Second Timer 555 (CB25745E)
This basic relay configuration was found in a July 1994 Electronics Now. The relay is supposed to be...
OR Gate Using NAND (CB197E)
An OR gate can be improvised using NAND gates of a 4001 as shown here. The diodes are...
Comparator with Feedback diode (CB5072E)
We find this circuit in the 80's own component manual. The power supply should be from 4 to 30 V...