9 Aug
2004
9 Aug
'04
2:21 p.m.
No, the
streams were just digitized radar video.
Yeah, no kidding! * the CRTs deflection yoke mechanically rotated in
sync with the radar
dish via Selsyns & servos;
By the 1950s, the rotating yoke was mostly out of fashion, save a few
World War 2 designs that refused to die. Even some World War 2 PPI scopes
did away with them, doing the rotation electronically (SCR-584, for one).
* map overlays, if any, were either transparencies
applied to the CRT
face, or electronic ones were a lucite mask over another CRT, complete
with rotating yoke in sync with the main display, and a phototube that
picked up the "map" outline on the lucite, and summed the "map"
voltage
in with the radar analog data;
This is how the SAGE AN/FSA-10 gap-fillers worked - the scopes of up to
six radars were directed at one radially scanned image tube. The result
was a composite radar video stream.
William Donzelli
aw288(a)osfn.org