My introduction into 'real' RF was in 1989 by a finnish engineer at Salcomp. They had a spectrum analyser that took a waveguide as input....
The guy takes his calculator , types a few minutes, scribbles some numbers down, takes a tape measure , cordless drill and a drill bit and a pencil. Walks to the waveguide, measures some locations and marks em in pencil. Drills a few holes , and sticks in some self tapping screws.
He looks at the analyser screen and turns the screws deeper or shallower until he had the right bode plot.
There i was, 18 year old kid , looking at it with glazed over eyes realizing 'that stuff really is black magic'