The antenna requires a loading coil for each band. I made coils for 40m, 30m, 20m and 15m to match an Elecraft K1 I have.
The coils are built from 3/4" PVC risers with threaded caps on each end. Through each cap there is a bolt, 5/16" on the upper end and 1/4" on the lower. Each bolt connects electrically to a terminal ring, with RadioShack hookup wire used for the windings.
The top two bands:
The 30m and 40m coils have a lot more wire on them. I had to add a few turns on each of these before getting the SWR down right inside the bands:
On each coil there is a 5/16" bolt and 1/4" bolt. The 5/16" bolt is on the top of the coil, and connects with the threaded coupler attached to the base of the whip:
When building the coils and attaching the bolts, first be sure to purchase flat topped pipe caps. Rounded caps just won't work, and will be really difficult to drill to get the bolts vertical. Also, use star washers both inside and outside to lock down the assembly. You'll need to tighten this enough so that the act of attaching and removing the threaded couplers does not loosen the coil hardware.
The other end of the 20m coil with a 1/4" bolt:
