We make them and use them all the time in East Texas.
We use the following.
5') 4" Light gauge PVC (like is used for drain & vent lines)
1) Slip on cap for the top
1) 4" Y
1) 4" Drain grate like you would use for floor drains
This is the same as I make mine and they work very well. I had a bear destroy one the night before bow season about 3 years ago. If a bear ruins one, your not out alot of money.