My dad took the vacuum tubes to be tested in one of those at Graham Electronics in the basement of Glendale Shopping Center. Behind the counter at Graham were racks containing bins with every type of vacuum tube.
That memory was the inspiration for my post.
My older brother lived at Graham Electronics, buying whatever he needed that could not be cannibalized from dad’s old electronic junk in the basement. He built radios from scratch at age 14, and built a music synthesizer from component parts when he was 21.