Go portable with your Butternut vertical.
Do you use your Butternut vertical for portable operation like, Camping, Field Day or Dxpeditions? We all know how easy it is to damage the inductors and doorknob capacitors! Here is how to protect the 40 and 80-meter coils and the doorknob capacitors without dissembling that section of the antenna. On the HF2V these are the only coils you need to worry about. On the HF6V the 30-meter coil is easy to remove and reinstall and so we just remove it and place it in a box while transporting the antenna. If you don't use 30-meters you can leave it off eliminating the requirement of tuning that band. The HF9V antenna has two more coils for 12 and 17-meters that would be difficult to remove and reinstall. Simply use the same construction technique as used for the 40 and 80-meter coils. The material used for the construction of the coil shield is 4-inch PVC sewer pipe (the cheap stuff), one 4-inch T, and two 4-inch caps. Hardware required is a 1" X 1/2" brass finish corner brace, one suitable brass wood screw, and a 1 1/2"-inch hose clamp. You will need a, 1 1/4" hole saw, jigsaw, and a hand drill or drill press. Below is a picture of the completed coil shield assembly.
The 1 1/4-inch hole saw is used to cut the slots in the pipe along with a jigsaw. The technique is simple. Drill two holes for the ends of the required slot and then using a straight edge draw a line on each side of the holes and use the jigsaw to remove the pipe between them. I only cut one slot for access to the coil clamp wing nut used for adjusting the 80-meter coil, as this is all that was required. For the 40-meter coil cover I cut four slots. This is done for access to the coil clamp wing nut and allows you easy access to the 30-meter coil tap point. If this point happens to be between slots simply turn the upper pipe a little as no glue is used in the pipe joints. The two end caps have a 1 1/4-inch hole drilled in the center of each to clear the antenna element and keep the coils centered in the pipe.
A four inch PVC "T" is used for protection and clearance of the capacitors. Below is a close up picture showing how it's done.
Note the aluminum straps passing through 1 1/4-inch clearance holes in the pipe "T". The coil shield will slid up and down without something to hold it in place and could damage the capacitors. This is where the 1" X 1/2" corner brace, hose clamp, and screw is used as shown in the picture below.
Here is a picture of the top end of the coil cover.
The coil shield will lower the frequency of operation slightly after it has been installed. You might need to readjust the coils. Simply follow the tuning instructions in the manual for your Butternut vertical antenna. The cost of this project was less than $15 USD. That's cheap insurance for your Butternut antenna. I wish I had a HF9V antenna so I could detail construction of the 12 and 17-meter coils! Also check out the Butternut-antennas yahoo group if you enjoyed this article at