A while back we had a skunkworks project that needed to pass CISPR 11 but also had ~0 budget. Initial testing in a rented chamber revealed a grossly-failing amo

A while back we had a skunkworks project that needed to pass CISPR 11 but also had ~0 budget. Initial testing in a rented chamber revealed a grossly-failing amount of energy emitted that had a clear peak but covered a fair bit of spectrum. The solution was to head out to a nearby field and set up a Yagi antenna at one end and an easy-up and generator to power the device at the other. This allowed a few months testing for ~free, and with a fast loop of "iterate design" -> "retest" -> "repeat". It wasn't great testing, but suitable enough to tell if the frequency we cared about was improving and by how many dB.