This circuit, of a Popular Electronics of 1969 is destined to firing a gas LASER of the time. The circuit makes use of a high voltage transformer for triggering.
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...