02-12-2008, 10:10 AM
Sometimes baking a coil in the oven will help, in that baking eliminates moisture that the coil has absorbed over the decades.
Bake it at 175 to 200 degrees for a half-hour or so, with the coil sitting on edge; DO NOT lay it down on its side.
After baking, seal the coil with a few coats of lacquer. DO NOT use wax to reseal the coil, even though Philco used wax originally! When these sets were new, it was thought that wax would keep moisture out. It doesn't. In fact, wax will not only allow moisture in, but it will serve to KEEP moisture in!
I have a 40-201 on the bench now, with tracking issues. 1280 kc comes in at 1420. I suspect the oscillator trimmer assembly, as the high end AM trimmer is tight, and the mounting is loose. It's been forced before. Wonderful...
Tom, on your pushbutton assembly, have you cleaned it? You may have to remove, spray the contacts with tuner cleaner and brush them with an old toothbrush while the cleaner is still wet. Those contacts are notorious for going intermittent/bad, but usually they respond well to a good cleaning. And always replace both 370 pF caps with new mica units (I see you have already done this).
Bake it at 175 to 200 degrees for a half-hour or so, with the coil sitting on edge; DO NOT lay it down on its side.
After baking, seal the coil with a few coats of lacquer. DO NOT use wax to reseal the coil, even though Philco used wax originally! When these sets were new, it was thought that wax would keep moisture out. It doesn't. In fact, wax will not only allow moisture in, but it will serve to KEEP moisture in!
I have a 40-201 on the bench now, with tracking issues. 1280 kc comes in at 1420. I suspect the oscillator trimmer assembly, as the high end AM trimmer is tight, and the mounting is loose. It's been forced before. Wonderful...
Tom, on your pushbutton assembly, have you cleaned it? You may have to remove, spray the contacts with tuner cleaner and brush them with an old toothbrush while the cleaner is still wet. Those contacts are notorious for going intermittent/bad, but usually they respond well to a good cleaning. And always replace both 370 pF caps with new mica units (I see you have already done this).
--
Ron Ramirez
Ferdinand IN
