Resistance reading jumping all over the place

[veecee]

That normally means you have a looser connection or the coil its shelf is touching the chimney. Undo the screws/grubs and re tighten them and make sure the coil isn't touching anything.

i think the coil might have been touching the chimney. I installed a new coil and lowered it and that gave me a stable resistance

 

[Crispycritters]

a stretched out coil, is that like a spaced coil?

Yes.

Sometimes the current can miss a turn or two in a contact coil and take a short cut missing a turn or two - this is more prone in a small build deck where a complex coil can be a tight fit. Stretching out the coil/spacing it means the current can't 'jump' across any turns that are in tight contact with each other and has to travel through the entire coil.

 

[LordOdin]

a stretched out coil, is that like a spaced coil?

Yeah stretched out and spaced are the same thing, less chance of hotspots. I prefer not spacing and if placed correctly you should be abled to get rid of hotspots quite easily. Smaller coils tend to space a bit when you add cotton sometimes.