Eighty years ago, the radio repairman was a heroic figure, as shown by this illustration on the cover of the April-May 1941 issue of National Radio News.  While the lady of the house and faithful canine companion look on, he is getting this set back into operating condition.

Perhaps he had to replace a tube, or perhaps he was resetting the set’s pushbuttons.  This was necessary since the FCC had just changed the frequencies of most U.S. radio stations on March 29, 1941.  An article in the magazine included a timely feature going into detail on the circuits involved.