We found this circuit in the April 1978 issue of Radio Electronics magazine. The 2-digit circuit uses common TTL integrated circuits and must be powered by 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...