This TTL circuit was found in an American documentation from the 80s. The components are common in the series and the supply must be made with a voltage of 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...