Armstrong began calling monster truck races in the early 1980s, and he is still active in the sport. Armstrong got his start with the fledgling monster trucks in the early '80s, calling an event at the Astrodome in Houston. He then moved with the sport when the trucks made their TV debut at the National Farm Machinery Show in Louisville. Over the seasons, he called events on ESPN and TNN, in addition to his work with the truck and tractor pullers and swamp buggy racing. He's still calling National Tractor Puller Association events broadcast on RFD-TV.