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.
In this short article, I’d like to share a trick I learned today while checking the power supply of my trusty Tektronix 7104 oscilloscope. Step A2 of the calibration section in the manual calls for measuring and adjusting the pre-regulated 109V voltage at test point TP1326. Normally, accessing this test point requires removing the power supply cover, which takes time and exposes high voltages. The test setup shown in the title picture demonstrates how to access this test point while keeping the power supply cover in place.
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.
One of the most valuable instruments in my collection is the Tektronix current measurement system, which consists of an AM503 probe amplifier and the accompanying A6302 AC/DC probe. While the probe itself doesn’t need much attention beyond the occasional wipe to remove dirt from the jaws, the amplifier recently became quite noisy in several attenuator positions. So, I decided it was time for a thorough spring cleaning.