There is not a lot of information about this camera. The model made before this was the TE 14/TE 15, but the TE 20 is even more rare than those models. It was made for surveillance type use, but is extremely large for a security camera, and weighs close to 20 pounds!! This may have been one of GE's first non-broadcast type cameras. It's very over-built for a simple surveillance camera, every single part of it is metal! As you may notice, it has a very unusual design, as it's shaped like a cylinder, and the electronics are built around a rectangular frame on the inside (see photo 5.) It didn't come with it's lens, but the lens I put on it here is as close as it's gonna get, as it is also a GE lens.
It's all solid state, being made in the mid 60s when everything started being transistorized. On the back, there are the standard controls for beam, target, and focus, and there is a switch to switch the target voltage from being in "manual" to "auto." Obviously, the "auto" position will automatically vary the target voltage, but they didn't label it ASC or ALC, I guess that term wasn't around yet. There is also a UHF video out, and a slot for a fuse. The tube is a 1 inch vidicon. It's in amazingly good condition being from 1965, and looks almost brand new! It is currently not operational, and I will try to troubleshoot it once I have the service manual.