While making some measurements today, I noticed a strange reflection in the signal generated by my Tektronix 7S12 TDR sampling plugin. At first, it looked like a bad connection at the output of the loop-through S-6 sampling head. However, after further testing, it turned out to be a more serious flaw.
I’m a proud owner of several Tektronix 7000-series mainframes. Among them, the 7904— a 500 MHz, 4-compartment oscilloscope—for many years served as my bench workhorse. The screen is large enough, the bandwidth is adequate for the majority of tasks I perform, and the absence of a cooling fan makes it pleasantly quiet. Additionally, the instrument is relatively lightweight compared to other 7000 mainframes and has legs mounted on the rear panel, allowing it to stand vertically on the floor.