Radio Direction Finding Set AN/TRD-4A
Main Equipment rack AN/TRD-4A Direction Finder Set. Operators spent a considerable amount of time in front of this or newer but similar equipment over the years. -- Scanned photos from Army Technical Manual.
On the right side - Tried to get the neon effect we actually saw when using this scope but did not do that good of a job but hope it gives some idea. (You might see this image being used in a Tee-shirt and other items on the net.) I made this image about five years ago when I was making the earlier logo .gif image for the web site.