The PHILCO Phorum

 Hard sometimes to believe how much wire is on the small bobbin. Project for tomorrow.

Weigh the wire and bobbin together, then weigh the wire alone. Spool the new wire on the bobbin until it reaches the weight of the combined items. Usually you're with 1 or 2% of the needed resistance at this point provided you're using the same guage wire.

Thanks Jim for the advice. I will give that a try.