The History of WKBO . . . the beginning
WKBO started out as WPRC in October 1925. according to Stevenson's Buletin of Radio Broadcasting in January 1926, WPRC was owned by Wilson Printingg & Radio Company and was at 216 metters and 100 watts.  It was WCOD for several years in the late 1920s and early 1930s beforef becoming WKBO. In 1929, the station was owned by Norman R. Hoffman and the call letters were WCOD. And in 1931, the station was purchased by Keystone Broadcasting Organization. Sometime in late 1933, the call letters were changed to from WCOD to WKBO (for Keystone Broadcasting Organization). The call letters WKBO had originally been assigned to a station in Elizabeth, New Jersey. Steinman Broadcasting acquired the station sometime in the late 1930s. Steinman also owned WGAL AM-FM-TV, Lancaster (now 1490 WLPA and 101.3 WROZ) as well as WORK, YORK (now 1350 WOYK). Steinman also owned the Intelligencer Journal Newspaper in Lancaster. All of the broadcast properties were eventually sold except for Delmarva Broadcasting consisting of WDEL and WILM. Also, in the 1930s, the station moved its facilities to 31 North Second Street in Harrisburg in a building that still exists today. Special thanks to Harrisburg radio historian Timothy Portzline for his help. Information in this section was also compiled from David Gleason's website including Stevenson's Bulletins and White's Radio Logs.
This is the information supplied by Timothy Portzline
I traced the timelines of all the commercial land stations that existed in Harrisburg in the 1920s. According to the listings in the Federal Radio Commission's Radio Service Bulletins, four stations held licenses simultaneously from 1925 to 1927: WBAK, WABB, WHBG, and WPRC.

Starting with call letters WKBO and tracing backwards in time, all records of ownership and call letters for WKBO stop (begin?) with WPRC. WPRC started in October 1925. (It was WCOD for several years in the late 1920s and early 1930s before it became WKBO.) There is no indication in FRC records that WKBO was connected with any stations prior to WPRC in 1925.

FRC records also show that WABB was on the air from 1924 to 1927, meaning that WPRC and WABB overlapped for two years (1925 to 1927). Obviously WPRC and WABB could not be the same station if they overlapped!

In 1927, WABB completely disappeared from FRC records with no indication of a sale to a new owner or a change of call letters. The station folded, as did WBAK in the mid 1930s.

According to the most reliable sources, the two oldest remaining stations in Harrisburg are WHP (starting in February 1925 as WHBG) and WKBO (starting in October 1925 as WPRC).

Call Letters & Frequency: 
  The call letters: WPRC ---> WCOD ---> WKBO
  The frequency: WKBO was not always at 1230.
Originally WPRC was at 1390 on the dial. in 1928 WPRC was at 1430. In January 1929, WPRC was listed at 1200. In October 1929 as WCOD it was also at 1200. As WKBO it remained on 1200. In 1941, the North American Regional Broadcast Agreement rearranged the radio dial, and on March 29, 1941, 802 of 893 AM stations shifted frequency. WKBO moved to it's new home at 1230 am.
WKBO was the first of the Steinman stations to be sold. In 1971,  Harrea Broadcasting, with Michael Rea as principal and J. Albert Dame as  25 per cent owner, acquired the station. Steinman, however, was not known for lavish spending and WKBO had not performed very well over the years. It certainly was not without notoriety, as it broadcast live Wilt Chamberlain's record breaking 100 point game at Hershey Sports Arena in 1962. With more on the pre- Harrea era, here's John Summers who worked at WKBO from 1971-73:
"WKBO had a non-descript middle-of-the-road format of the Englebert Humperdinck/Tom Jones variety.  NBC News on the hour.  NBC Monitor, a music-and-personality service used by many small NBC stations, ran all weekend.  Not a bad station, really, just no real need for it.  A typical low-budget Steinman operation, almost totally dependent on downtown advertisers, who were closing-up fast by 1970.  Good personalities, Charlie Adams and Gary Brooks among them."
WKBO The Station On The Go . . .
Before 123 Radio KB and The Rock of Harrisburg. WKBO was the Station On The Go. Still owned by Steinman, WKBO was an NBC affilliate. Captain Dave Provides these 1960s pages from a station sales brochure. Personalities during this incarnation of WKBO included Gary Brooks, Joe Thomas, Charlie Adams, Doug McKay, Toby Young and Buck Benson. Scott Alan was news director.
"The old WKBO was not without merit, however.  When hearings were held into Harrisburg's racial disturbances of the late 1960s, WKBO carried them gavel-to-gavel, the only Harrisburg station to do so.  They allowed Toby Young to do a "soul" show from 6-9pm weeknights, and for a while in the summer of 1970 there was a guy who did a sort-of progressive rock show from 9 pm - 1 am.  They also had a talk show, "Voice of the People," which aired mornings from 9 til 10.  The host was a guy named Joe Thomas, a real rabble-rouser and very entertaining."

In 1971, WKBO was in a bad way. It was generally 4th in a then 4-station market (FM hadn't really begun to develop yet). It's 1930s era equipment, including the 1938 Western Electric Board, was showing its age. The transmitter and tower were located on top of the Old Penn Harris Hotel (now where Strawberry Square is located). The ground system wasn't maintained and hence, WKBO's class IV 1,000 watt day/250 watt night signal was the worst in Harrisburg.

Harrea Broadcasting had a lot to gain and little to lose.

Next: Hurrea takes over and 1 - 2 - 3 Radio KB Begins . . .

Jeff Roteman's WKBO Website