This decoder circuit 3 of 8 was found in a publication for PCs from 1992. The circuits are TTL and must be powered with 5 V.
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....
This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common...
16 commercial test circuit for tubes and transistors appeared in Radio Electronics magazine in...