Although KDKA'a initial licence didn't mention that it would be used for a broadcast service, a year later that information was included,in its second licence, issued November 7, 1921, although the station continued to also be used for a point-to-point radiotelegraphy "traffic" between Westinghouse facilities. Following standard practice, the serial number for the Limited Commercial licence remained "174". (There would have also been a Form 761: Applicant's Description of Apparatus associated with this licence, but I do not have a copy of that in my files).

In the fall of 1921, the four Westinghouse stations (KDKA East Pittsburgh, Pennsylvania, WJZ Newark, New Jersey, KYW Chicago, Illinois, and WBZ Springfield, Massachusetts) moved to a common wavelength of 360 meters (833 kilohertz), and included is engineering information documenting that the KDKA transmitter was operating effectively on this wavelength.

 
KDKA second licence (November 7, 1921) - 1st page

KDKA second licence (November 7, 1921) - 2nd page

KDKA second licence (November 7, 1921) - 3rd page

KDKA second licence (November 7, 1921) - 4th page

KDKA second licence (November 7, 1921) - Supplemental