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Expansion on your fun fact. Electronic rotation was accomplished with a polar CRT. A polar CRT is a variant of a vector CRT where the beam path starts in the ce

Expansion on your fun fact. Electronic rotation was accomplished with a polar CRT. A polar CRT is a variant of a vector CRT where the beam path starts in the center and extends to the edge in a direction derived from the azimuth of the radar antenna. The transmit pulse would start a new scan from the centre and its speed would be determined by the desired range selection. Finally the beam intensity was just the amplified return signal from the antenna. All of this required complex electromechanical devices to generate (and eventually filter) the required signals. As technology progressed and textual information started to be added to the process it became necessary to convert the polar plot to a conventional rasterized signal. This was accomplished with a scan converter tube which was essentially a polar CRT coupled to a TV camera. Radar would plot on the CRT and the camera would turn it into scanlines to be overlaid with data. This was used into the 90s and there's probably still operational systems relying on this.

ddingus 3y ago
In the 90's I got an inside tour of PDX airport. They had these systems and a camera pointed right at one to rasterize them. At the time, a whole lot was still analog. Beautiful systems. Saw one of those 9 track tape drives too. On a seek, tape would just dissappear from one reel and accumulate on the other one --fast! And then CLACK! It would stop and just start reading at what looked like normal speed. Was kind of impressive in its own way too.
- MadnessASAP 3y ago
  Being in the air force I have the dubious privilege of getting to maintain some old ass-technology. Radar being amongst my favourites. We've since upgraded to comparatively modern technology (digital!) and gotten rid of most of the vacuum tubes but I still have a special dark place in my heart for the old mixed signal system running on CRTs, wire wrapped boards, tapes, and core memory. Interestingly while the new system is much nicer to work with, much better resolution and features I didn't think were possible. The old system had power, and lots of it, and sometimes power is what you need.

ddingus 3y ago

In the 90's I got an inside tour of PDX airport. They had these systems and a camera pointed right at one to rasterize them. At the time, a whole lot was still analog. Beautiful systems. Saw one of those 9 track tape drives too. On a seek, tape would just dissappear from one reel and accumulate on the other one --fast! And then CLACK! It would stop and just start reading at what looked like normal speed. Was kind of impressive in its own way too.

MadnessASAP 3y ago
Being in the air force I have the dubious privilege of getting to maintain some old ass-technology. Radar being amongst my favourites. We've since upgraded to comparatively modern technology (digital!) and gotten rid of most of the vacuum tubes but I still have a special dark place in my heart for the old mixed signal system running on CRTs, wire wrapped boards, tapes, and core memory. Interestingly while the new system is much nicer to work with, much better resolution and features I didn't think were possible. The old system had power, and lots of it, and sometimes power is what you need.