Yeh,
Radio Shack is a good starting point.
What I've gotten into the habit of doing for decades now, is whenever I plug a cable into a jack, whether it be a guitar jack, a speaker jack, ..whatever, I always test the nut by just putting my thumb and index finger on the nut and giving it a light twist. If it moves, time to tighten it. If it doesn't, it's secure for a while longer.
Just me, I guess, but I've found loose nuts on monitor cabinets that haven't moved in months and seems like the nut on my Ovation will loosen up at least once a year.
FWIW
