I copied the large scrap wood feeder idea from the learning center.

Look under "large feeders" for the original concept. I added a hinged top cap to prevent roosting on top. Used 3/4" plywood and 3/4 OSB board that I had laying around. Also had a piece of an old cabinet (the blue part at the bottom) which was also 3/4" thick. I used a piece of this for the angled piece on the inside that directs the feed into the trough. The overall height is 48", just a bit taller than the original. Hinges were about $2 at Lowes.
The plexi glass (10"x8" .080" thick) was about $4. Since I started from scratch, I screwed the plexiglass from the inside before assembly. Figured it would help keep the feed from trying to push it out.
We are going to paint it shortly. We have some paint laying around from past room paintings in the house. I'm letting my wife and daughter come up with the color scheme based on what paint we have. I'll try to remember to get another picture of the painted product.
If you have any questions about dimensions, let me know!