An Easy HF Antenna
When radio amateurs get ready to put an HF station on the air, they often have questions about what antenna to use. The good news is that there are many options to choose from. The bad news is that there are too many options to choose from. It can be overwhelming. This post describes an antenna I just installed that is easy to put up and works well.
Having 30-foot tall pine trees on our property, my usual approach for HF antennas is “wires in the trees.” I have several ropes strung up over these tall trees so that I can raise and lower wire antennas as needed. These ropes were installed using a slingshot to launch a fishing line over the top of the tree, and then pull up a lightweight rope.
End Fed Long Wire
The antenna is the EFLW-1K from MyAntennas.com, which is an End Fed Long Wire Antenna. (This should not be confused with an End Fed Half Wave antenna.) This antenna is intentionally cut to not be a resonant length on any of the bands. The 9:1 UNUN transforms the high impedance at the end of the wire down to something closer to 50 ohms. The match is not perfect so an antenna tuner is required to cover all of the bands. MyAntennas offers this antenna with different lengths of wire, with longer wires required to support the lower HF bands. I purchased the 53-foot version but decided to shorten the wire. My interest is working 20 meters and higher and I wanted the antenna to be mostly vertical, so I shortened the wire to about 30 feet. The MyAntennas products are good but any 9:1 UNUN on the end of a wire will work.
An endfed antenna like this needs some kind of counterpoise to balance out the antenna operation. Many people have written about this and there are many different approaches. The MyAntenna UNUN has a connector intended to support adding a short length of counterpoise wire. A decent length of coaxial cable lying on the ground can function as this counterpoise and that’s what I decided to use. I have a 50-foot length of LMR 400 connected to this antenna, lying on the ground.
I also added an inline isolation transformer to minimize the common mode currents getting back to the transceiver. I don’t know that this is required but I had one available so I used it. The antenna has 50 feet of LMR coax to the inline transformer and then another 25 feet of RG-8X to the transceiver. The internal antenna tuner in my Icom IC-7610 handles this antenna quite well, tuning up on 20m, 17m, 15m, 12m and 10m. This means I can instantly switch between the bands and be ready to go.
I’ve been running SSB, FT8 and FT4 on this antenna, working many stations in all regions: Europe, Asia, Oceania, Africa, North and South America. Conditions are great and I keep telling newer folks: now is the time to be on HF! This basic antenna is a great way to get on the air and work some DX.
73 Bob K0NR
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