A little more on SPG-59 -- here's the tangled nest of waveguides (with many removed) on the 3,400-element test installation on land. The calculating sphere is visible.
![[ img ]](https://i.postimg.cc/Jzjz48Yy/spg-59-waveguides.png)
Of course, to preserve phase information, each of these had to be the same length to within a fraction of the wavelength of the radar.
You can imagine why this design did not mature into a practical service system! Planar phased arrays required much more in the way of computer horsepower, but were fantastically more practical with another ten or fifteen years of technological development.
Here is some much more in-depth further reading (PDF warning). I may need to revise my receiver-array setup.
