The upcoming GCARC Dummy Load / Wattmeter build project date is almost here! This build is set for Saturday, 10 May as the May 2025 Tech Saturday Forum topic. The cost per seat is fifty dollars, and plenty of seats are still available.
This instrument is unique in that it is a dummy load that will report to the user the power level of the signal that is being sent into the dummy load. It can be built at any one of three maximum power ratings, 25 watts, 50 watts, or 100 watts, which is decided upon at the time of building the unit. This is an interesting combination of basic electronics in the dummy load section and advanced electronics operation in the fact that the reporting wattmeter is based on an Arduino Nano. All of the heavy lifting will have been done for you before the event — the programming of the Arduino and the finely detailed assembly of the interconnecting wire harnesses. The design uses two circuit boards, each of which you will assemble during the build, and it is almost 100% through-hole componentry. The only solder joint that is not through-hole is the connection of the load resistor to the detector PCB.
This instrument is one that belongs on every ham operator’s benchtop, as it serves the purposes of both a dummy load and a wattmeter, as its name implies. However, the wattmeter function is automated and requires no fancy manipulation of menus or programming once the firmware is loaded into the Arduino. What could be easier?
Think about it seriously, and then, if you decide that you could use an instrument like this one, sign up for the build by completing the form below…