Great radio amateurs of yesteryear:
The late Rudy Van Gelder (W2TMD) was a master recording engineer whose music studios in Hackensack and Englewood Cliffs, New Jersey were used in many famous jazz sessions on the Blue Note, Prestige, and Impulse record labels.
“Rudy got interested in electronics early on, and he became a radio ham when still a teenager. In those days, much of the professional audio equipment was designed and built in-house. The large record companies had electronic engineers on staff that would take care of their needs; Rudy did much of it himself.”
This 1947 callbook reference shows Rudy’s original QTH, which was his first recording studio.
Rudy’s 2011 interview by Don and Maureen Sickler is here — https://tinyurl.com/e9tv3yej
In time present, the Sicklers manage the Englewood Cliffs studio.