A friend of mine has an old Tram D201A as well as a couple other old tube radios, that are in mint condition, but have'nt been plugged in for at least 15-20 years. I heard that to get them up and running again, we need to start them up slow through a "variac" to prevent damaging the caps. My friend was able to get a variac from his boss, but I want to know what the CORRECT way to do this is. Do we just plug the radio into the variac, turn it on, and start turning up the voltage slowly, or do it in steps? Neither one of us any experience with a variac and very little with tube radios, especially ones that have been sitting for so many years, and we hate to ruin such a nice radio.