Here is mine,
Started with two small (2' X 2') Overhead Transformer pallets
that I got from the local utility. I do not have drawn plans.
The photos are pretty self explanatory I think,
everything was "glued and screwed" using Gorilla Glue.....
Hope this helps, I am sure there will be plenty of other ideas.
Here's the one I built. It beats chaining it to a tree which I was doing before I built this. I also like that I can move the PHD around without hooking it up.