I keep mine outide resting on top on the enclosure. Two things to remember about uvb lighting. 1 - Make sure the cham cannot touch the bulb and burn itself. 2 - Make sure your cham can get at least 12" from the bulb, as the uvb won't be strong enough further away than that.
I don't have my laptop at the moment so I can't post a pic..
The enclosure I have is a screen homebuilt one. The frame and the back are made of wood and at the moment I'm keeping it the uv right at the top inside. My panther doesn't get any natural sunlight..
