Backpack-able HF Antennas
As with the radio or rig itself, key issues for a practical HF antenna for a long wilderness backpacking trip should be light, consume little space in your pack and be easy to put into operation. To fit well inside the pack with everything else they need to be physically flexible. My experience with backpacks is that they are stuffed absolutely tight with few "straight areas" for anything rigid or more than a foot or so long. I suppose you could hang some rigid pieces on the outside but the likelihood of damage as the pack gets tossed around on the ground and getting snagged as you clamber through the brush seem like hassles to me. So I lean toward wire antennas. They can be relatively efficient, eminently flexible and fit into a pretty small space.
PAC-12 Rigid vertical |
 Home brew Pac-12 vertical in use on family vacation in Minnesota.
Several years ago I ran across the PAC-12 vertical and had some success with my home built version. But for our upcoming six day, four night trip in Glacier National Park it is out due to weight and form factor.
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Dipole |
A dipole is a very good candidate. The down side seems is the requirement of a feed-line and the need for two supports. Of course an inverted Vee configuration makes supporting it easier. A possible negative is that they are generally single band antennas.
A video by K1YPP talks about two portable antennas that caught my eye. The simplest is simply a dipole attached directly to the radio with no feedline or tuner. He suggests it can be configured either like a Vee (as opposed to an inverted Vee) by throwing both wires up into trees. Or you can put one in a tree and the other on the ground. I haven't tried this yet but it sounds interesting. The limitation is that it is a single band antenna.
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Magnetic Loops |
Another very interesting antenna is the small magnetic loop antenna. Commercially they are kind of expensive. Could one build one that would work? One I saw being discussed by members of the 4SQRP club recently is the Alexloop. I'm not in any way promoting it, it is just one example.
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End Fed Antennas |
End fed wires are another option. I've played with half wave version in the past but never very seriously. But for this trip I want to explore them more thoroughly as they have the potential of multi-band use which is attractive. A potential negative for almost all end fed wires is the requirement of some kind of tuner or matching network. Two that matching approaches I've had some success with are a simple tuned-secondary transformer with very small primary. I describe it in detail on the page for End Fed Half Wave antennas. The other one is called the Tuna Tunah ii offered by QRPme. Both are built in a tuna tin, so pretty are small and light.
The second antenna suggested by K1YPP in his video is a 51 ft wire and a counterpoise tied directly to a tuner. Another variation I've seen is a 35 ft wire and counterpoise, and I've experimented with using the 33 ft 40 meter half wave on other bands with some success. |
My plan is to explore some of these options, especially the wire antennas as they seem like the best candidates as I see things now.
