Note
Radio, May 1937, p. 91.
QST, Jul 1937, p. 81.
Originally known as the Patterson PR-15, it was rechristened the Pierson-Delane PR-15 in 1937 when Patterson's chief engineer, Karl Pierson, formed a new company with a man named De LaPiane. The 15-tube receiver's circuit was the same as its Patterson cousin. There were minor cosmetic differences.
References
Brief review. Radio News, Sep 1937, p. 145.