I've been working on a 2m setup for hiking. My goal is to have the best possible antenna that can be used while walking, and that won't get damaged if I walk under a low branch or some other forest obstacle.
The setup so far: Off the top of a backpack with a steel frame I mounted a Diamond SRH77CA whip. It is connected by a very short length of coax to the HT in a side pocket of the pack, and then I have a speaker/mic clipped to a shoulder strap:
So far, so good, and the whip has proved to be both rugged and stable in its mounting.
In order to further improve the antenna's performance, I added a "Tiger Tail" counterpoise, following the directions here. (There's more about the theory behind that here.) It's a roughly 19" wire, 14ga, hanging from the base of the antenna down the side of the frame pack. According to the theory, this "transforms the 1⁄4-λ whip into a full-size center-fed 1⁄2-λ dipole". Yay for theory.
The PDF with the directions notes, "The hardest part of using this Tail is getting the wire to hang straight," but with the backback frame right there, I anchored it down the side using small zip ties in a few spots, and it's running straight up and down.
Now, the question: is the steel frame of the pack possibly messing with the performance of the Tiger Tail? Does a counterpoise need to hang in free space to work properly? Or by providing a solid, well-defined counterpoise path with that wire, have I prevented the antenna from capacitively coupling to the steel in the frame?
Thank you for your help, antenna wizards...