My thread tensioner applies absolutly constant tension to the thread. Tension is easily adjustable and is maintained even if you must wind backward to correct overwraps etc.
I'll give you the basic idea and if you like it you can adapt it for your own use at little cost.
Here's my setup: My wrapping station is a desk which is against the wall. The thread spool is in a lightweight fly tying bobbin.The bobbin tension prevents thread from unwinding but allows more thread to be pulled off when needed. A soda straw scotch taped to the bobbin horizontally prevents spinning which would unfurl the thread. The thread goes up through a screw eye in the ceiling very close to the wall and down to another screw eye in my wrap stand. A wine cork on its side is screwed though its center to the wrap stand. Pulling the thread under the cork prevents the thread from escaping when the thread is cut after a wrap is finished. The bobbin is hanging from the ceiling screw eye. Gravity provides the tension. I adjust tension by adding lesd wire to the bobbin. If the ceiling screw eye is located where the bobbin can hang almost to the floor, 2 or 3 wraps can be completed before the thread must be adjusted.
I wrap by holding the rod in both hands. The rod can be moved in any direction without losing tension.
I only use the wrap stand to hold the rod after the wrap is completed.
A lot of words for something so simple. What do you think?