Signedprinted on back of cone: 540-AW / TRADE MARK / Western Electric / REG. U.S. PAT. OFF. / PAT. IN U.S. JAN. 18 1921 PATENTS APPLIED FOR / MADE IN U.S.A.
Inscribedprinted on back of cone: UNLESS SPECIALLY LICENSED OTHERWISE TO THE PUR- / CHASER THE APPARATUS IS LICENSED UNDER PATENTS MARKED / HEREON, FOR USE ONLY FOR ONE WAY WIRELESS TELEPHONE / RECEPTION OF PROGRAMS, AND WITH REFERENCE TO SUCH / USE IT IS FURTHER PROVIDED: (1) THAT SUCH APPARATUS MAY / BE USED IN CONNECTION WITH A WIRE DISTRIBUTING SYSTEM, / FOR RETRANSMITTING SUCH PROGRAMS, BUT ONLY FOR DIS- / TRIBUTION TO AN ASSEMBLED AUDIENCE OR TO ROOMS WITHIN / A BUILDING OR TO A GROUP OF SUBSTANTIALLY ADJACENT / BUILDINGS COMMONLY OWNED OR OPERATED. THIS APPARATUS / IN EACH CASE TO BE LOCATED IN THE IMMEDIATE VICINITY / OF SUCH AUDIENCE OR WITHIN THE BUILDING OR GROUP OF / BUILDINGS WITHIN WHICH SUCH DISTRIBUTION IS MADE; / (2) THAT SAID APPARATUS SHALL NOT BE USED IN COMBINATION / OR IN CONNECTION WITH PHONOGRAPHS.
in red on base: 1929 / WE 540
FunctionTransduces electrical signals into sound
Related Workshttps://www.radiomuseum.org/r/western_el_540_a_w540a_hornless_loud.html