If you use a file, be sure to maintain the bevel. Two methods I use: starting with a 10" single cut file, lay it flat on cardboard, or workbench, lay the two blade with surface to work on, flat on file, and stroke from handle to tip of file 1-3 times per side and then the opposite. Remove burr with a leather strope (belt).
Second, use a wheel sharpener, like a RADA, or Firestone 2-stage wheel sharpener (Amaz--). Some have two wheels side by side, total of four wheels, which are better IMO. Wheels are steel, or ceramic. Some only have two wheels. It gives it a hollow ground. Sharpening can be harder than it should be, because the flat bevel tends to get rounded, the wheel prevents that. Since using the file (laid flat), and/or the wheel, it only takes a few minutes to put a sharp edge on a blade. I use the wheel for knives followed by stroping. It is easy to carry the two afield.
A trick with the wheels is a short, light pressure, back and forth with the blade vertical, so it removes minimal steel from both sides evenly. With the file, I like to point the tip of the broadhead straight down the center of the file, with light pressure. Use light pressure with either method.