Tracking Arm installed beneath 300-foot telescope
The 300-foot telescope in Green Bank, West Virginia was a transit telescope, meaning that its dish did not track objects across the sky but watched them as they arced overhead. In the early 1970s, a tracking arm was installed up on the feed arm to slowly move the receivers in time with the movement of the sources the telescope was observing.
Credit: NRAO/AUI/NSF
