The signal chain frontend is a delicate piece of radio-frequency engineering. Heretofore, components development, characterization, and testing have been done in controlled indoor environments such as the shield room at the MIT Haystack Observatory and the anechoic chamber at MIT Lincoln Laboratory. Recently, the completed KPGO frontend was taken outdoors for comprehensive radio testing under realistic open-sky conditions. The frontend tests exercised all subsystem components but the horizontal positioner, which largely provides mechanical coupling to the antenna. The tests confirmed high-quality measurements in the high-frequency band. Despite the radio-quiet time enforced during the tests at Haystack, radio signals from mobiles and other wireless devices are ubiquitous in the low-frequency band. Suitably, signal interference is known to be less of an issue at the KPGO site.