[stevehertz]

If an amount of 'pre-testing' is carried out, there is little or no need to 'limit' the mains supply to a vintage radio in my opinion. As I touched on earlier, I always test, reform or change as appropriate main smoothing caps. I change all waxies on sight. I clean all switches, pots and sockets (including valve sockets/bases), remove and test valves, check for shorts across the mains, HT to chassis etc. And then, carefully apply full mains using one's eyes, ears and nose to monitor the situation. Workwise, it's probably not a lot different to switching on using a variac or a lamp limiter as the aforementioned issues will have to be tackled at some point anyway. But doing it this way, they're already eliminated as a source of trouble. We're all different, I get that, but personally I see little point in gradually applying mains to a set that in your heart you know is probably riddled with faults anyway. Just sort them out, eliminate them and that 'worrying' switch on is likely to be a more of a damp squid that an indoor fireworks display.