Sorry David, I don't have one, in case nobody comes along with and answer before you need to sharpen it, use a marker pen..
Simply colour in the entire bevel with a marker pen rest it on your chosen sharpening system at the angle you think it is and turn the wheel / belt / whatever by hand if it removes a clean line from one end to the other you guessed right, if it only removes at the base then too high an angle / tip to low an angle.