This simple modification, originally described by tinhead on the EEVBlog forum, is intended to make the built-in cooling fan quieter. A common issue with cooling fans is the noise they produce, and a typical solution is to reduce the voltage (and therefore the current) supplied to the fan, causing it to spin more slowly. The Hantek DSO5000-series oscilloscopes feature a three-terminal 12V voltage regulator dedicated to the fan (indicated by an arrow in the title image). To adjust the fan voltage, I simply need to replace the regulator labeled U7 on the power supply PCB.
Some time ago, I realized that I needed to add a digital oscilloscope to my set of instruments. A DSO is handy for making measurements and capturing screenshots—something I've been doing a lot lately. After comparing the specifications of current models from several manufacturers, I chose the Hantek DSO5102B. The main reasons for selecting this model were its cost, screen size, and strong potential for hacking—though not necessarily in that order.
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.