The 80(75) Meter Linear Loaded Dipole
I wrote this page because there is no instructions that I can find on the web about an 80 or 75 meter linear loaded dipole. The reason I wanted a linear loaded antenna for that band is because a full half wave antenna is so long. I wanted an antenna that would be about as long as a 40 meter antenna.
So, without any further adieu, here is what I came up with.
I was able to scrounge up some 5.5" (14 cm) OD PVC pipe as some insulator/support. I cut two pieces into 3" (8 cm) lengths for the end of the loading sections.
I drilled holes as illustrated in the figure above. Make two of these. The spacing of the holes aren't too critical, but try to keep them as far apart as possible.
The center (feedpoint) piece is about 7~8" (19~20 cm) long. Again, drill holes as seen in the illustration above.
Cut 2 pieces of wire using the common formula for finding the length for antennas (468/f(MHz)). For mine, I chose to go with 3.8 MHz. So the length was 123.157' (37.538 meters ). Cut that exactly in half, and there are your 2 wire pieces of the dipole.
Drive two stakes 13.12' (4 meters) apart in the ground. Put the center piece around one stake and one of the end pieces on the other stake. Thread the wire through the pieces as illustrated above. When one side is done, remove the first end piece from the stake and put the other end piece there and thread the other side with the 2nd piece of wire the same as the first.
Above is a picture of the finished feed point. Tie a knot or use a wire clamp near the end of the wire that will connect to the transmission line.
Here is one of the finished end pieces. Note the wire clamp at the right side of the support piece.
At the ends of the antenna, you may need to add a capacitance hat as illustrated here. I used 3' (1 meter) of 12/2 romex wire. Strip the wires bare and fashion them as you see here.
Here is a shot from an end. This may help you with what yours should look like.
I hope this works for you as well as it does for me.