I'll second that. Both my NC-183,183D, and various other vintage rigs
ran very hot at my nominal line voltage, here, of about 120-125 volts.
I now use a Variac in power distribution line for the older radios and
set it at 110v. The drop in temp of the transformers was dramatic....
There may, of course, be other problems like leaky caps, etc. so a
complete check may be necessary. de K3HVG