8BaLL,
SPYDERCO Tri-Angle Sharpmaker is an excellent tool, it allows to obtain great results without difficulties. I recommend the Sharpmaker as primary sharpening tool in your home, but I think it isn't intended to field use. You need a solid base to work with Sharpmaker, table or working bench for ex. In really field conditions it can be pretty difficult to work with Sharpmaker and easy to lose it parts, in deep snow or high, thick grass for ex.
A set of SPYDERCO Pocket Stones 303M & 303F or double-sided Pocket Stone 303MF would be much better choice for field use, but you would need to place them on the flat solid base too.
If you need to restore your knife edge in really field conditions go to DMT Double Sided Diafold, I think Fine/Coarse one would be the best choice, especially if you have an axe in your equipment. With Diafold you can resharpen knife or axe even holding it in free hands, without any solid base. Of course this sharpening would be not as precise as if you would work with the Sharpmaker, but your knife will work. At home you can correct sharpening angle with Sharpmaker.
If you are extremely limited with weight conditions or/and use knife with serrated blade try GATCO Tri-Seps Serration and Knife Sharpener. It's one of smallest and lightest (if not the smallest and the lightest) really working sharpeners what I whenever saw and used. You can place it in your backpack, pocket or even on chain on your neck. Minor disadvantage - a bit tricky to work with, but possible.
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Sergiusz Mitin
gunwriter
Lodz, Poland