In the early 70s my father was an avid ham-radio operator - geeky before computers! He was always building ham gear and even hand-soldered one of our first FM amplifiers that I later took to college - loved that Heathkit!

I remember seeing him and his friends mucking with tons of gear including oscilloscopes. Even cooler (at least for a 9 year old) was camping at an ARRL field day and going cabin to cabin seeing every hand-soldered setup made.

I remember in particular the cool "Squelch" button on some rigs used to "tune" the grainy voices bouncing all over the ionosphere on the ham bands. The purpose was mainly to make morse code more audible or voices listenable but playing with that dial would always make the coolest sounds.