Westinghouse's election night broadcast from station 8ZZ, located at its plant in East Pittsburgh, Pennsylvania, was sent on a wavelength of 550 meters, which is equivalent to an operating frequency of 545 kilohertz.
The Radio Amateur, A Department for Wireless News, By C. E. Urban

Pittsburgh Gazette Times, October 24, 1920, Sixth section, page 4: (Full column at Google newspapers.)

    On Tuesday night, November 2nd, an opportunity will be presented whereby every amateur can demonstrate the practical uses to which radio may be put by receiving the returns from the presidential election on his wireless set, giving the benefit of this service to his fellow citizens. He has the advantage of being able to receive these returns right in his home, avoiding a trip to the business section of the city when thousands have to stand in a jostling throng on the streets. The amateur can also invite his friends to enjoy these advantages with him. ...
    Not only will the returns be broadcasted by wireless telegraph, but the Westinghouse company in East Pittsburgh plans to announce the returns by wireless telephone, sending out radiophone music between times, on a wave length of 550 meters. This will make it possible for persons who are not acquainted with the telegraph code to hear these returns announced by word of mouth at any amateur radio station they may have access to. A good suggestion would be for amateurs in Pittsburgh and other cities especially the smaller towns, to arrange for community gatherings which could possibly be held in local schools and churches where they could set up receiving apparatus and by means of a loud speaker, such as the magnavox, or a baldwin phone combined with a phonograph horn, have these returns and music produced for the benefit of the entire gathering.
Has  300-Mile  Range.
    As the radiophone to be used by Westinghouse has a range of 300 miles this should be very easily accomplished by any ingenious amateur. At the same time he could copy the returns received by radio-telegraph and have an assistant chalk them on a blackboard. W. K. Thomas, a well-known amateur of Pittsburgh, will operate the Westinghouse radiophone on election night. Tomorrow, Monday night, at 8 p. m. an initial test will be made by the Westinghouse people, with their phone, in connection with the local A. R. R. L. representative, Mr. Williams, at station 8ZD, and the Radio Engineering Society, to establish certain wavelengths for this work will not conflict or cause interference on election night. The society will not transmit, but listen on various wavelengths. Starting October 29, Station 8ZD will send out QST announcements regarding the plans for election night.
    Besides the tests to be made by Westinghouse on Monday night they will make announcements on Wednesday and Friday nights on various wavelengths so that amateurs within range can become acquainted with tuning them in on the wave length to be used on election night, 550 meters, to which wavelength they will jump at regular intervals. The plans made by the Westinghouse company are the reason for the change in the A. R. R. L. program whereby Mr. Williams, at Station 8ZD, will broadcast the returns from Pittsburgh instead of Mr. Conrad, at Station 8XK, as Mr. Conrad, who is employed at the Westinghouse plant, will be needed there on that night to assist in their radio work.
    It will be clearly understood, of course, that the success or failure of the whole plan depends upon the amateurs themselves. It is absolutely essential for success in this scheme that all amateur transmitters, except those designated to do the broadcasting, QRX on the night of November 2 from 7 o'clock on, and either copy or permit the copying of election returns continuously on that night. We have been requested to announce here that this is urgently requested by Mr. Conrad (8XK), the Radio Engineering Society of Pittsburgh and the American Radio Relay League, through its local representatives. All amateurs are further urged to aid the cause by circulating this information among their radio friends before November in order that there may be no QRM on that night.
October 31, 1920, Fifth Section, page 10: (Full column at Google newspapers.)

A BIG time for radio amateurs is promised Tuesday night when the returns of the presidential election will be received by many thousands of amateurs throughout the country. Special preparations are being made in many communities, where there will be gatherings to get the returns as they are received by amateur radio stations installed at school houses, halls, churches, etc., for this purpose. In many of the smaller towns this will prove to be quite an event. At Indiana, Pa., the Boy Scouts of Indiana county are planning a big Scout rally for election night, the special feature of which will be a banquet and reception at which the election returns will be received via wireless by means of a receiving set installed for the occasion, and employing a loud-speaking instrument so that every person in the hall or at the banquet table can hear the latest returns announced by wireless telephone without leaving their seats.
Plans  Complete.
    In Pittsburgh, all the plans discussed in this department last week for radio work on election night have been completed. Preliminary tests have been made and proven very satisfactory. It is predicted that, weather conditions permitting, the radio men will accomplish their stated objective of beating the regular wire service in giving the election returns to the general public. In the tests made by the Westinghouse International Radio Telephone Station (8ZZ) at East Pittsburgh direct communication was established with stations in West Virginia and Ohio and at distances of nearly 300 miles, proving the effective range of this radiophone to be all that they anticipated. The Westinghouse people have equipped their offices and plants at Derry and Mansfield, O., also at Louisville, Ky., with radio receiving sets to receive the returns for posting on bulletin boards on election night.
Many  to  Hold  Meetings.
    The Edgewood Club of this city has arranged for a gathering at which they will have loud speaking telephone apparatus combined with an amplifying receiver to pick up the returns being sent by wireless, telegraph and telephone, so that the entire audience in a ballroom will be able to hear the returns.
    The Radio Engineering Society announced that at their meeting last Friday evening all plans were completed and arrangements have been made with the William Penn Hotel people to place a canvas screen on the Sixth avenue side of the hotel on which to throw the election returns they will receive by wireless in the Public Safety Building, using a stereopticon machine for this purpose.
    In order that there may be no chance for failure on the part of the radio amateurs to carry out their plans on election night we have been asked to mention a second time in this column that the American Radio Relay League and its local affiliated organization, the Radio Engineering Society, as well as the radio division of the Westinghouse Company, who will all be co-operating in the sending and receiving of election returns by radio, wish to make a special request to all the amateurs of this vicinity to refrain from transmitting after 7 p. m. on Tuesday night November 2.
November 7, 1920, Sixth Section, page 3: (Full column at Google newspapers.)

    The returns by wireless telephone, which were transmitted from the Westinghouse international radio station at East Pittsburgh, were exceptionally clear and distinct. The service was utilized by many amateurs to entertain gatherings at their various stations. Between announcements of the returns radiophone music was transmitted, which added much to the entertainment.