Radioland will be able to tune in on a new broadcasting station beginning March 4, next. It will be station KWBC, now being installed at the Warner Brothers studio on Sunset Boulevard, at a cost of approximately $50,000. ... The station, named with the last three letters representing Warner Brothers Classics, will not be a commercial proposition, nor will it be used for the exploitation of Warner Brothers pictures, Sam Warner said yesterday.

Station KPRC—“Kotton, Port, Rail Center”—the Houston Post-Dispatch’s big new 500-kilowatt broadcasting station, took the air in its official debut at 8 p.m. Saturday....

Regarding the decision of Ross Sterling, Sr., to start a Post-Dispatch radio station, it's been reported in several sources that it was his son Ross, Jr., who was interested in radio and talked his dad into taking action. Boudreaux says Sterling had two sons, Walter and Ross, Jr., and both were interested in radio and convinced their dad to buy the 500 watt Westinghouse Electric transmitter. Additionally, when the decision had been made to proceed with the station after a period of mourning over the death of Ross, Jr., Sterling turned to his son Walter to name the station. He picked the call letters KPRC to stand for Kotton Port, Rail Center. I don't know that anyone has claimed for sure who picked the call letters though I had speculated it was Daniel's suggestion.

With the change came a new set of call letters, WLBL for "Wisconsin, Land of Beautiful Lakes." The originally requested WLOL was not available because the federal government then required that all four-letter call signs have a B as their third letter. After all such call letter combinations were exhausted, C could be the third letter, and so on. Stevens Point officials were satisfied with the WLBL call letters and felt that "they form a good descriptive slogan for state publicity".

The reference for the above information is page 1 of the May 12, 1924, Stevens Point Daily Journal.

Thanks to Thomas White for this information.

However, the new station list in the Sept. 1, 1925, RSB showed WOCG in Sycamore, licensed to Triple Alliance Radio Station.

On Nov. 2, 1925, the RSB reported WJBN (which was alphabetically assigned) was the call for the newly station of St. John's Evangelical Lutheran Church in Sycamore.

An Oct. 14, 1925, newspaper article reported that the church had requested WOCG, for "Watch our City Grow," but was was issued WJBN instead. WJBN was licensed on Oct. 6.

The Jan. 30, 1926, RSB reported that both WJBN and WOCG had been deleted.

Thanks to Thomas White for this information.

“Why stay up north?” was adopted as the official slogan about a month after the station signed on the air. However, I have seen nothing to explain why the call was chosen. It would seem that “sun” or “sunshine” could have been the reason.

WWJ: The Detroit News, issued by the station in 1922, explicitly states (p. 82): “WWJ is not a person. WWJ is The Detroit News radiophone station. WWJ is not the initials of any name. It is a symbol.”

In his 1989 autobiography, Radio's First Broadcaster, Elton Plant wrote (p. 36):

On March 6, 1922 the call letters became WWJ. WBL being scrapped as hard to understand when heard over the air. If you can imagine, we used to get mail addressed to WCL, WEL, WDL, WGL, WPL, almost everything but WBL.

“WWJ — Pioneer in Broadcasting,” by Cynthia Boye Young in the December, 1960 (Volume 44, #4) issue of Michigan History, has the following (p. 423):

The present call letters of the Detroit News station, WWJ, were adopted in March, 1922, replacing the first commercial call letters, WBL. The reason for the change is explained by Edwin Boyes. When the fad was raging to pick up distant stations,⁵¹ people often sent postcards to the transmitting station to inform them that their programs were being received at great distances. WBL was sent hundreds of cards, addressed not only as WBL, but as WGL, WDL and other combinations of letters that sounded the same. Interference on the air waves and noise on the receiving sets made it difficult to hear call letters clearly. Hence, it was decided that letters would have to be chosen that would be more easily recognized through the interference. This need was made known to radio inspector Edwards who in turn requested the commissioner of navigation to assign new call letters to the Detroit News station.⁵²

The station had requested WKL or WWW. However, in a letter from Edwards dated March 6, 1922, they were informed:

You will also note your call has been changed from WBL to WWJ. This is about as good as we could do in the matter of call letters and we hope that you will find them satisfactory.
—

⁵¹Distance seemed to interest listeners more than quality of reception.

⁵²Samuel W. Edwards to the commissioner of the Bureau of Navigation, February 1, 1922, in the Detroit News file.

(Edwin G. Boyes, mentioned in this recap, is listed as a WWJ engineer since 1922)

As noted above, the station requested either WWW or WKL. However, during this period call letters with the same letter repeated three times were not permitted, so WWW was not available. Also, according to the May, 1922 edition of The Consolidated Radio Call Book, WKL was already assigned to a ship called the Mexican. Station lists in the Call Book indicate that the following WW- calls were already assigned:

WWA China Am ss
WWC Western Wave Am ss
WWD Arcadia Am ss
WWE Manchuria Am ss
WWF City of Para Am ss
WWH Newport AM ss
WWI Pennsylvania Am ss Pacific Mail Tugboat Co.
WWK Western Queen Am ss
WWL San Jose Am ss (P. M. SS. Co.)
WWM San Juan Am ss
WWN Mongolia AM ss
WWP Ausable Am ss
WWQ Bellefonte, Pa., U. S. A.
WWR Rose City Am ss
WWS Alaska Am ss
WWU Hazelhurst Field, N. Y.
WWV Washington, D. C., U. S. A.
WWX Post Office Dept., Wash., D. C.
WWY Slocum Am ss

This left WWB, WWG, WWJ, WWO, WWT and WWZ as the only unassigned WW- calls, so it appears that Edwards just choose the most phonetically dstinct of the WW- calls that were still available. This information on WWJ was contributed by Thomas H. White.