The best way is to count turns as you unwind and use the same number rewinding. Maybe there will be a broken wire at the termination?
AES (tubesandmore.com) and Play Things Of Past (oldradioparts.com) both sell replacement coils. An universal replacement coil has an adjustable center core but are only for broadcast band.
Norm
:I'm looking at the possibility that I will need to rewind an RF coil. Where can the info be found ?