The SCR-658 radar is a radio direction finding set [1] introduced by the U. S. Army in 1944,[2] was developed in conjunction with the SCR-268 radar.
Its primary purpose was to track weather balloons.
Prior to this it was only possible to track weather balloons with a theodolite, causing difficulty with visual tracking in poor weather conditions.
The set is small enough to be portable and carried in a Ben Hur trailer.
There is one known survivor at the Air Force museum in Dayton Ohio.