160 Meter Loading Coil
As in other shortened vertical antennas I have built, I went to the online shortened vertical calculator to find out what coil I need to build. Based on my wire length on the mast and the inductance required, I came up with a coil 2 3/4 inches in diameter, and 13 inches long with 94 turns.
Making your own coils can be a bit difficult however I saw a Facebook post how W0BNC used Panduit Grommet edging and PVC pipe to make loading coils for vertical antennas. I was able to find some grommet edging on Ebay and 2″ PVC at Home Depot. Remember, pipe diameter is measured by its inside diameter, so with the wall thickness, and the grommet edging, the coil diameter comes out to 2 3/4″.
For the wire, I used galvanized steel wire used for electric fences. I chose this as it is obviously more weather resistant than copper wire, which tarnishes. The photo above shows the grommet edging glued the length of the PVC pipe. The wire for the coil fits nicely into the slots of the grommet edging.
At each end of the PVC pipe I drilled a hole for an 8-32 stainless screw. This serves two purposes. First this is where the coil is started and second, this is where I attach the vertical wire that is on the mast. Winding the coil can be tricky as it can get tangled up as it comes off the spool. As you can see in the photo on the right, I used a milk crate and a dowel rod through the center of the spool. This was in essence my third hand in the winding process.
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