Modern Mechanics Mechanical TV Receiver
This design for a mechanical TV receiver, published in the 1932 How to Build It issue of Modern Mechanics, would not have worked. First, it was designed for 24, 36 and 48 line transmissions. By 1932, none of these standards were in use. Almost all transmission was done with either 60 line/20 fps progressive scan, or 45 line/15fps triple interlace.
In addition, the viewing window is on the side of the disk, which would have worked for vertical scanning lines, but all American transmission was done using horizontal scanning. The viewing window needs to be at the top of the disk.
Obviously, this design was never built by Modern Mechanics. I wonder how many other things in the magazine were also not tested before the designs were published.