[BC] need a NON-technical explanation

[Tom Taggart]

I have a White's Radio Log from 1932 that lists stations by
both wavelength and kilocycles.  Somewhere I also have a
1927 Dayton Radio directory that listed stations just by
wavelength (but it also listed stations by the dial settings
for the radios they made).

I suspect the change from wavelength to kilocycles came
about primarily for marketing purposes, and reflected the
evolution of broadcasting from a hobby to an entertainment
medium.  When my mother was a senior in high school in
Pawtucket R.I., my grandfather built a "wireless" receiver
and was thrilled to pick up KDKA. This would have been in
1922. 

Remember that in 1922 the electric starter for cars was a
relatively new invention (1912), and most cars were still
hand-cranked. Radio broadcasting was just beginning to grow.
 By the time my mother graduated from college, she drove to
her first job (teaching at a college near Roanoke, Va.) in 
a year-old Model T, complete with special added on electric
start & super low gear for bad roads. By that time (1926)
probably half the country had radios, and the Congress was
debating the creation of a new agency to control
interference (the Federal Radio Commission, 1927).

Radio receivers went from hobbyist toys run off batteries to
fine furniture that plugged into the wall during this same
period.  Go look at the ads in some old National Geographic
magazines from that period. So the operation of the "radio
sets" had to be simplified for the consumer, which meant the
use of kilocyles instead of meters for dial indications. For
example, the White's 1932 listing for WBZ and WBZA:

WBZ/WBZA Westinghouse  E. & M. Co. Boston 302.8 (W.L.); 990
K.C. (or)
WJAR The Outlet Co., Providence 336.9 (W.L.); 890 K.C.

A lot easier to set your radio dial to 990 or 890 or even to
1410 (WAAB, Boston)then to some oddball fractional number
representing the wavelength.

In Europe, especially after the development of shortwave
broadcasting in the mid thirties, (as well as the use of
long wave broadcast) I suspect wavelength continued in
common usage much longer.  After all, it's still the
"Deutsche Welle" ("German Wave").

Good luck on your dissertation.  My girlfriend just
completed her masters.  Didn't exactly bring the fame and
fortune she thought it would (but sociology is not exactly a
path to great riches).