WLW's 500,000 Watt Transmitter

Mike Check K5UCQ


Neat history of this station. Nice video tour of the station transmitter

*Published on Jul 19, 2013 *
While In Dayton Oh at Hamvention 2013 I attended a tour of the WLW AM
broadcast transmitter facility located in Mason Ohio. WLW has kept a major
piece of broadcasting history alive by keeping much of the old high power
transmitter intact.

Back in 1932 WLW increased their power from 50,000 watts to 500,000 watts.
They were the only AM broadcasting station in America ever to operate at
500,000 watts. Much of the old transmitter still exists. It is really a
high power amplifier with a high level modulator (360,000 watts). The
amplifier was driven from their existing 50,000 watt Western Electric
transmitter. The system used 20 100,000 watts tubes ($1,600 each in 1932)
that required water cooling that used a cooling pond located outside the
station. Tons, and tons, of hardware was required to achieve the 10 dB gain.

Before the 500 KW went on the air, WLW installed a Blaw Knox vertical
radiator, or as we say today a vertical antenna. Back in those days a
horizontal wire flat top antenna supported by two towers was common. Photos
in the video show the impressive antenna farm at WLW.

The engineering was state of the art pushing the 1930s technology to
achieve 500,000 watts. Operating the transmitter required a team of many
engineers to bring it to life and control it while it was on the air. A
simple ON-OFF switch did not exist!

Enjoy the tour of the facility and the history of this high power station.
Thanks to Jay, Geoff, and Ted of WLW for hosting the tour.

I will soon post another video the covers the collection of 50,000 watt
transmitters that are also in the same building.

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