I use a Olympus DS-30 and have had good luck. It is best to record starting about a month before your season. Place it about ten yards or so in front of you so that the movement sounds you will certainly make do not degrade your recordings. The hens will be excited and very vocal at that time. Once they begin nesting they will become Sphinx-like and under normal conditions all you get will be gobbling, which can get boring in a hurry.