San Francisco was the site of one of the first major wireless stations in the United States with the founding of the "Poulsen Wireless Corporation of Arizona" in 1910 and, later, the Federal Telegraph Company. Though called an Arizona company, it was founded here in San Francisco and transmitted from a site on 48th Avenue between Noriega and Ortega streets, at the Ocean Beach.

Primary force behind the commercial development of Valdemar Poulsen's arc wireless transmission method was Cyril Frank Elwell (1884- 1963), a Stanford student who convinced the inventor to license his patents in the United States to him.

Elwell enlisted the aid of several Stanford University professors who understood the scientific possibilities of the Poulsen system. He went to Europe and spent several months there involved in experimental wireless work with the inventor.

Poulsen's agreement with Elwell required that the patents could not be turned over to any existing telegraph companies because Poulsen feared they would throttle development of wireless communication.

The young Stanford graduate engineer returned to the United States, formed a company with his Stanford colleagues, and built Poulsen wireless stations in Sacramento and Stockton. Hans Buhl, curator of The Steno Museum - The Danish Museum for the History of Science and Medicine, wrote:

Elwell was based in Palo Alto, and his first company was the California-registered "Poulsen Wireless Telephone & Telegraph Company" founded in 1909.

The method of generating continuous electric waves by means of a light arc was invented by the Danish engineer Valdemar Poulsen (1869 - 1942) in 1902 as a modification of Willian Duddell's "singing arc" from 1900.

The arc transmitter was not Poulsen's first important invention. In 1898 he invented the Telegraphone, which allowed recording of sound on steel wire. This invention was the foundation of all types of magnetic recording including audio and video tape recording, computer hard disks and the magnetic strip on credit cards and metro tickets etc.

Elwell, in his autobiography, wrote that the first San Francisco station was placed on "a block of sand dune-covered land 240 by 600 feet at 47th and 48th Avenue and N and O [Noriega and Ortega] Streets facing the Pacific Ocean," and that "a 9,000-foot length of used Geary Street [cable car] cable was cut and used as guys for the masts" of the first antenna towers to save money.

Just after the company was formed, Elwell hired inventor Lee DeForest to develop practical receiver amplifiers for the Poulsen wireless system.

Founders of the companies were Beach Thompson, president; E.W. Hopkins, vice-president; Howard P. Veeder, secretary and treasurer; Cyril F. Elwell, chief engineer; John F. Deahl, J. Henry Meyer, Stanford engineering professor Charles D. Marx, Carl Philip, George A. Pope, and S.E. Slade members of the board.

Later, during the 1920s, control of the Federal Telegraph Co. passed to San Francisco financier Rudolph Spreckels.

Howard Veeder, Federal's secretary and treasurer, wrote in the July 1912 edition of Pacific Gas and Electric Magazine:

In San Francisco the Company's present wireless station is located close to the Ocean Boulevard, [the Great Highway], about one-half mile south of Golden Gate Park. The towers sustaining the antenna are of the Howe Truss type and are 300 feet in height, the material is wood, and the towers are uniformly six feet square from base to top. In the operating house there is installed both a 12-kilowatt and a 30-kilowatt Poulsen generator, together with the receiving panels and other apparatus necessary for the use of either generator. This allows one of the generators to be always in reserve. The current required for the use of these Poulsen generators is 600 volts direct current. This is supplied by the installation of a 50-horsepower motor- generator set, which is installed in a separate power house and which changes the 220-volt alternating current supplied from the mains of the Pacific Gas and Electric Company to the 600-volt direct current needed. There is also a spare motor-generator of the same capacity.

The antenna at the San Francisco station has a total length of about 21,000 feet of wire. The wire used is seven-strand phosphor bronze, which is especially strong and durable.

Elwell left the Federal Telegraph Co. in the summer of 1913 because of disagreements with Beach Thompson. He was succeeded by the young engineer Leonard Fuller who played a crucial role for the practical development of high-powered Poulsen arcs.

Wireless telegraphy was of great military importance to the United States, and the Navy comissioned station FNN, at Arlington, Virginia, in 1912, with Poulsen arc transmitters. During the First World War many battleships were equipped with Poulsen transmitters, and the U.S.S. George Washington, which carried President Wilson to the Peace Conference, was able to transmit a 600-word message from Brest back to the United States about the President's arrival.

Poulsen stations were taken over and used by the U.S. Navy during World War I. In 1921 the Poulsen patents and stations were given back to Federal Telegraph Co. which, between 1921 and 1923, built new stations in San Francisco, Portland and Los Angeles.

All the Federal-Poulsen stations were apparently sold to Mackay Radio in the late 1920s, but the company continued to manufacture transmitter apparatus, and equipped the AT&T shortwave site at Dixon, California, with modulators as late as 1944.

Elwell later wrote "The Poulsen Arc Generator" published in 1923 by Van Nostrand Company, and continued to write about electronics until 1959.

An interview with Stone gives a fascinating glimpse into the early history of amateur and commercial wireless in the San Francisco Bay Area. He was also author of the popular "Elements of Radio Communications" published in 1926 by Van Nostrand Company.