THE RADIO HISTORIAN
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 WLW Cincinatti - Powerful Transmitters

In 1934, WLW became the first and only United States AM station to operate with the massive power of 500 kW. It was a huge investment on the part of Powel Crosley, Jr. WLW operated at this power level under an experimental license until 1939, when Congress and the F.C.C. decided that the maximum power for any broadcaster would be 50 kW. The massive transmitter seen in these images has sat idle since 1939, but is still in place today in WLW's Cincinnati facility.

In January, 1925, WLW stepped up from 500 to 5,000 watts with the installation of a new Western Electric 5C transmitter at Harrison, Ohio - 25 miles from its studios.
Another view of the WLW 5,000 watt transmitter, with the station's transmitter operator, Joe Whitehouse. WLW was among the first U.S. stations to use this power level.
To increase power again to 50 kW, WLW moved to this Mason, Ohio, transmitter site of WSAI, which Crosley acquired in 1928.
Construction of the new WLW transmitter building at the WSAI site.
Another construction view
Aerial view of the WLW - WSAI site in 1928
The completed WLW transmitter building at Mason, Ohio.
Western Electric 's first 50 kW transmitter, the model 7A, was installed at WLW in 1928.

WLW 500 kW Super-Power Transmitter

The WLW 500 kW transmitter plant, completed and in operation, 1934.
Another view, showing the operating spray pond, a part of the transmitter's water cooling system.
A view of the 500 kW transmitter during installation.
One of the three 180 kW G.E. high powered amplifiers that were combined to produce 500 kW.
The high power modulator of the 500 kW transmitter
The 831 foot WLW Blaw-Knox diamond tower.
An aerial view of the site, with the WLW tower at the bottom, and two WSAI towers at top.
Another aerial view, showing the two supressor towers in the background, which were installed in 1935 to reduce WLW's radiation towards Canada.
An interior view of the completed transmitter installation
A main entrance view, showing the 50 kW Western Electric transmitter at left, and the 500 kW amplifier in the distance. The audio control room is at right.
A view from the operator's desk, looking towards the Western Electric transmitter, which served as a driver for the 500 kW amplifier.
Manufacturer's photo of the WLW transmitter control desk.
Powel Crosley Jr., seated at the control desk.
Another view of the transmitter operator's desk.
Margaret Carlisle, Mary Alcott, Ethel and Dorthea Ponce, and Flo Gorden, holding a row of transmitter tubes.
WLW program personalities at the transmitter site to broadcast the transmitter's official inauguration, May 2, 1934 - (L-R) Joe Emerson, Margaret Carlisle, Carl Grayson, Mary Alcott, John Barker, Johnny Muldowney, Flo Golden, Don Becker, and Henry Thies
WLW program personalities at the transmitter site to broadcast the transmitter's official inauguration, May 2, 1934 - (L-R) Joe Emerson, Margaret Carlisle, and John Barker
Powel Crosley, Jr., and Chief Engineer Joseph Chambers, moving one of the 100 kW tubes used in WLW's 500 kW amplifier.
Another view of Powel Crosley with one of the twenty UV-862 100 kW water-cooled tubes used in the big transmitter.
Audio control panels at the WLW transmitter site. They processed the program audio sent by phone line from the WLW studios.
RCA 870 mercury vapor rectifier tubes, part of the plate voltage power supply, rated at 1,200 kW at 12,000 volts.
Three filament motor generators for the 500 kw transmitter - 1500 amps each.
Powel Crosley, Jr., inspects the transmitter's control relay panel.
The plate transformers and reactor were located outside the building.
The two Westinghouse modulation transformers used at WLW, weighing 37,000 lbs. each.
Output coupling network for one of the three final amplifiers, showing tank and coupling coils, electrostatic shield, and air-dielectric condensers.
This 33,000 volt Cincinnati Gas & Electric substation provided the power needed to run the massive WLW transmitter.
The WLW antenna tuning unit, located at the base of the tower.
780 feet of coaxial transmission line connected WLW's 500 kW transmitter to the Blaw-Knox tower.
Setting the base insulator in place for the Blaw-Knox 831 ft. tower, 1933. The total weight on the insulator was about 450 tons.
A photocell arc supressor, installed at the tower base.
A closeup view of the photocell arc supressor. If it detected an arc across the spark gap, the circuit would temporarily disconnect the transmitter to extinguish the arc.
Field intensity meter and vehicle, used by WLW engineers to verify the station's signal coverage.
More photos of WLW:
WLW - The Early Years