The Lo-Z XR-Spectra coil:
- 1000 Turns
- 250Ω DCR (for 3.3″ version)
- 76mH
- AWG38 self-bonding magnet wire
- 2mm Type 430 ferritic stainless steel rail
- 1mm printed circuit board bobbin with copper-pour shield.
We use AWG38 self-bonding magnet wire (also known as bondable magnet wire). It has a thin layer of thermoplastic polyurethane adhesive, activated using 140~160°C hot air. The magnet wire is heated while winding, and again after winding. The result is solid and does not require any wax potting step. Here’s a cross-section of the bonded coil:
