immediately allow stations to use the full power. Instead stations could start operating with up to 1,500 watts, then, only if approved by the region's Radio Supervisor, increase powers in successive 500 watt steps, while ensuring that it was not causing excessive interference. In early 1925, WSAI and WMH moved to 920 kHz. The Commerce Department's cautious approach toward power increases was based on the assumption that station transmitters were located in heavily populated areas. However, in May 1925 it recognized that WSAI's Mason, Ohio and WLW's Harrison transmitter sites were both far enough from population centers that they could immediately begin operating as the first two stations in the nation transmitting with the full 5,000 watts. A Cincinnati Post writer investigated the effect of WSAI and WLW's May 11 introduction of the use of 5,000 watts, and found that despite claims that their "superpower broadcasting" would eliminate static within 500 miles, it was only "a start in the right direction". Listeners reported that the stations now sounded about twice as strong, and also noted that KDKA in Pittsburgh's 10,000 watts was even better. In mid-1927, WSAI was assigned to 830 kHz. In May 1928 the Crosley Broadcasting Corporation began leasing WSAI, and also began to consolidate WSAI's operations with WLW. This included WLW moving its transmitter site from Harrison to sharing WSAI's facility at Mason. Crosley moved the WSAI transmitter to a hilltop site overlooking downtown Cincinnati on Chickasaw Street, which later became the transmitter site of WLWT television. On November 11, 1928, under the provisions of the Federal Radio Commission's General Order 40, WSAI was assigned to 800 kHz. However, now classified as a "limited time" station, WSAI could only operate until sunset at the location of the frequency's primary stations, most notably WBAP in Fort Worth, Texas. In order to gain fulltime operation, in early 1929 WSAI moved to 1330 kHz, with a power reduction from 5,000 to 500 watts. WSAI was run as a locally oriented station, while the higher powered sister station WLW — with programs from NBC Radio and the Mutual Broadcasting System — aimed for the whole region. On March 29, 1941, with the implementation of the North American Regional Broadcasting Agreement, stations on 1330 kHz, including WSAI, were moved to 1360 kHz. The August 1941 adoption of the Federal Communications Commission's "duopoly" rule restricted licensees from operating more than one radio station