KUPR's operating wavelength of 270.1 meters corresponds to 1110 kilohertz.
 
Omaha (Nebraska) World-Herald, June 28, 1925, page 14:

Will  Attempt  to  Broadcast  From  Moving  Train
KUPR radio equipment
    First tests to determine the practicability of broadcasting from a moving passenger train will be conducted in August when the Union Pacific's "Calf Club" special sets out from Omaha for a trip through Nebraska.
    The broadcaster, to be installed in a dynamo car of the train, has been designed and built by Harold Hosford, radio operator at the Omaha Grain exchange. It is the same station used aboard the "Good Will" special trains of the Omaha and Sioux Falls Chambers of Commerce recently with many new features added. Arrangement will be made so a 1-thousand-volt generator will be driven direct from the dynamo or by auxiliary battery equipment, using the dynamo to recharge the batteries. This will make the station independent of outside power and will enable it to be operated while the train is in motion.
    The station aboard the "Good Will" special trains could only be operated when power could be obtained from a town at which the train stopped.
    The Union Pacific station probably will be known as "KUPR" and will operate on 275-meter wave length. The antennae will be placed as close to the roof of the car as possible and a counterpoise will be located beneath the car. It is expected the station will have a sending range of 1 hundred miles in August. Lectures on dairying and farm subjects will be featured.
Omaha World-Herald, August 2, 1925, Section E, page 11:

KUPR,  CALL  LETTERS  FOR  U. P. CALF  CLUB  SPECIAL
    The United States department of commerce has granted the call letters, KUPR, for the radio broadcaster to be installed year aboard the Union Pacific's Calf club special train, which will set out August 24 for tour of Nebraska in the interest of better cattle.
    The station will be installed in a special coach within the next two weeks by Harold Hosford, operator at the Grain Exchange station, WAAW. The station is being furnished by the McGraw Co. Wavelength assignment is being held up temporarily, but it probably will be fixed somewhere between 250 and 278 meters.
Omaha World-Herald, August 22, 1925, page 11:

CALF  CLUB  SPECIAL  WILL  HAVE  OWN  RADIO
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Will  Carry  Messages  From  State  Agricultural  Bureau  and  Public  Officials.
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SET  IN  SPECIAL  CAR
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    When the Union Pacific railroad Calf club special departs from Lincoln Monday morning on a tour to every vital point of agricultural Nebraska, radio will be an important factor in bringing home to farmers, stock and dairymen, messages from officials of state agricultural bureaus, Governor McMullen and associates of the railroad.
    At an expense of 6 thousand dollars, the Union Pacific, through the McGraw Electric company, Omaha, has installed in the special what experts have agreed is the latest innovation in mobile broadcast stations.
Radio  Instructor  as  Operator.
    KUPR, the Calf club station, with F. P. Durand, Technical high radio instructor as operator, will be operated on a wave length of 270 1-10 meters or 1,100 kilocycles, with 1 hundred watt amplification and modulation.
    The operating and generating of the station will be conducted in a specially equipped seventy-foot steel baggage car. Power will be generated entirely exclusive of an outside source, a feature said hitherto unattempted.
Has  Collapsible  Tower.
    A collapsible antenna tower that can be raised to a height of forty feet with an expanse of sixty feet has been erected upon the roof of this car. Tests made when installation had not been entirely completed brought reports from Dennison, Ia., and from various points in Nebraska according to Hal R. Edwards of the McGraw Co., who supervised installation and will be an observer on the trip.
    Lectures by dairy, farming and stock experts will be broadcast by day from KUPR, while each evening varied programs will be broadcast by talent from the town in which the special remains that night.
    The studio proper will be in the rear observation and business car of the eleven-car train, though provision has been made to transmit from any section of the train from the exhibition cars. A distinct feature in operation of the station is a thousand-foot microphone extension, permitting broadcasting from railroad stations, nearby farm dwellings or even in the center of the towns visited.
    The studio has been equipped with a Radiola "8" superhetrodyne receiving set by the McGraw Co., while the A. Hospe Co. provided a piano for use in the evening programs.
    To facilitate reception in the steel observation studio car, engineers have erected an outside aerial which will eliminate any possible interference.
Route  of  Travel.
    The itinerary:
    August 24--Start Lincoln 6 a. m.; arrive Stromsburg 9 a. m., exhibit until 1 p.m. Leave Stromsburg 1 p. m.; arrive Rising City 1:40 p. m., exhibit until 5:40 p. m. Valley overnight.
    August 25--Leave Valley 7:30 a. m.; arrive Fremont 8 a. m., exhibit until noon. Leave Fremont 12 m.; arrive Schuyler 1 p. m., exhibit until 5 p. m.
    August 26--Exhibit at Norfolk 8 a. m. until noon. Leave Norfolk 12 m.; arrive Albion 2:30 p. m., exhibit until 6:30 p. m. Genoa over night.
    August 27--Leave Genoa 7 a. m.; arrive Fullerton 8 a. m., exhibit until noon. Leave Fullerton 12 m.; arrive Central City 2:30 p. m., exhibit until 6:30 p. m. Grand Island over night.
    August 28--Leave Grand Island 7 a. m.; arrive St. Paul 8 a. m., exhibit until noon. Leave St. Paul 12 m.; arrive Grand Island 1 p. m., exhibit until 5 p. m. Arnold over night.
    August 29--Exhibit at Arnold 8 a. m. until noon. Leave Arnold 12 m.; arrive Kearney 3 p. m., exhibit until 7 p. m. Kearney over night.
    August 30--Sunday.
    August 31--Leave Kearney 7 a. m.; arrive Lexington 8 a. m., exhibit until noon. Leave Lexington 12 m.; arrive North Platte 1:30 p. m., exhibit until 5:30 p. m. Gering over night.
    September 1--Exhibit at Gering 8 a. m. until noon. Leave Gering 12 m.; arrive Broadwater 1:30 p. m., exhibit until 5:30 p. m. Chappell over night.
    September 2--Exhibit at Chappell 8 a. am. until noon. Leave Chapell 12 m.; arrive Sidney 1:15 p. m., exhibit until 5:15 p. m. Back to Valley during night.
    September 3--Exhibit at Valley 8 a. am. until noon. Leave Valley 12 m.; arrive Wahoo 12:45 p. m., exhibit until 4:45 p. m.
    September 4--Exhibit at Beatrice 9 a. m. until 1 p. m. Leave Beatrice 1 p. m., arrive Lincoln 2:30 p.m. Exhibit at Lincoln state fair following week.

Omaha World-Herald, August 23, 1925, page 10:

Radio  Broadcaster  Is  Installed  Aboard  Calf  Club  Special  Train
This picture shows radio station KUPR which has been installed in a specially equipped seventy-foot steel baggage car and attached to the Calf club special which leaves Lincoln Monday morning for a tour of chief agricultural sections of Nebraska. Lectures by dairy, farm and stock experts will be broadcast each day and varied programs given by talent found in the towns at which the special stops will be put on the air each evening. The station, installed by the McGraw Electric company at an expense of 6 thousand dollars, will be operated by F. P. Durand, radio instructor at Technical High school. It will operate on a wave length of 270 1-10 meters. KUPR radio equipment in baggage car

Omaha World-Herald, October 25, 1925, Section S, page 3:

Increasing  Nebraska's  Butterfat  Production
Boys' and Girls' CALF CLUBS, sponsored by the Nebraska Dairy Development Society, the Nebraska College of Agriculture, and various other interests in the State, promoting and executing the idea of better cows, rather than greater numbers.
    After winding up the tour at Beatrice, Neb., upon the afternoon of Friday, September 4, the train was run to Lincoln, and the dynamo baggage car, containing the radio sending station (call letters KUPR), the two coaches carrying the exhibits, the flat car and a horse car, containing the cows for demonstration purposes, were placed on a track near the Boys' and Girls' Club building.
    The total attendance at meetings through the car and at the radio programs was 35,355, which in addition to 34,480 that visited the train on the fair grounds, and inspected the exhibits, made the total attendance 69,835.
    In this conjunction, it should be remembered that the Union Pacific System, under President Gray's free scholarship plan, is the only railroad in the union doing such work, in co-operation with the extension division of the state agricultural colleges.