06-24-2008, 11:01 PM
18 gauge should be fine. But, why not just remove the crumbling insulation and slide on a piece of heat shrink? That's what I do. Far easier in my book, plus you keep the lengths proper. Which may avoid unwanted oscillation and/or noise.
-Brian
If you collect or are interested in antique telephones, please visit Classic Rotary Phones
http://www.classicrotaryphones.com/forum/index.php