Tuning In process is very critical in these regenerative receivers but very interesting. I always like to halt a moment whenever I heard a Morse Code signal with amusement. My bulky DLR-5 headphones gave me a satisfactory result both on voice and musics.
I am Assuming that Sub-Miniature vacuum tubes were not a thing yet in the 40's, at least to the general public. I know by the early 60's, they were used in hearing Aids, that was a box that hung around the persons neck, and 1 or 2 earphones. when I was in third grade, there was a girl at my school who had one of these.
