This HF antenna system that I built for my 817 works very well, and depending how you assemble the antenna, it can be used as a 1/4 wave vertical with a counterpoise directly on the radio as the one photo shows in the link below, or as a 1/2 wave horizontal dipole mounted on a walking stick. When used as a 1/2 wave horizontal dipole, it can be pointed in the direction you desire for the best signal. As a 1/4 wave vertical, I can work 6 meters through to 20 meters. As a 1/2 wave horizontal dipole I can work 6 meters through to 40 meters.
The Yaesu 817 with antenna, tuner built from a kit of parts, 7AH battery and solar panel for charging, all fit in a tiny backpack, as seen in the link below.
This antenna is extremely simple to build, as the coil form is already made in the form of threaded nylon ready-rod available from a bolt supply house. The 14 gage buss wire is wraped in the thread-form, and connected on either end to the PL259 connectors, that screw on to the existing threaded nylon ready-rod.