Nutone Century Model L49 1959
This PO-2 chime is believed to be the first long-bell door chime from the A.E. Rittenhouse Company. This chime is dated to between 1935 and 1936. Evidence of an early build is in it’s construction, The solenoid winding was apparently done by hand and the brass builders-plate is unlike later Rittenhouse door chimes. Further evidence is gleaned from a study of later marketing materials:
A 1970s era Rittenhouse Catalog claims:
In 1935 we developed the idea of a door chimes and the name Rittenhouse became synonymous with quality chimes.
What’s not clear is whether those earliest Rittenhouse door chimes were resonator, long-bell or compact chimes. A 1937 Rittenhouse brochure includes a resonator chime, a compact chime and two versions of a long-bell chime designated as the PO-3 and PO-4. All the Rittenhouse chimes in the 1937 brochure feature a musical note motif as shown in the Twintone. The PO-4 long-bell is a double-duty chime with two-notes for the front door and a single note for the rear. The PO-3 is a two-note chime for the front door.
The PO-2 is not mentioned in the 1937 brochure as it was presumably discontinued or distributed through alternate channels. An obvious question is whether there was ever a PO-1 chime.
A wiring diagram and instructions is pasted to the inside of the cover with directions on how to lengthen the spring if a “stronger second note is desired.” No provision was made for a decorative third bell.