You can make a feeder from a gallon milk jug.
Cut out half of the top, leaving the handle side alone.
Attach the handle to something in the coop--just run a string around it and tie to something.
Put some feed in the bottom, so it's about half full. That should be more than enough feed for four hens for a day.
http://mamamia5.blogspot.com/2010/07/home-made-milk-jug-chicken-feeders.html
This page shows one similar, but I put the hole higher in the jug (chickens have long necks, so they reach in just fine. And the deeper it is, the less feed gets spilled.)