The Electrical Experimenter, November, 1913, page 108:
Mr. Chas. D. Herrold, E. E., Chief Engineer, of the National Wireless Telephone and Telegraph Company, at his private laboratory in the Garden City Bank Building, at San José California, recently showed me the wireless telephone outfit which the Navy Yard Wireless Station, at Bremerton, Washington, reports having heard transmitting, "The Trail of the Lonesome Pine" as played by the phonograph on the morning of September 18, 1913.
This is an approximate distance of 900 miles.
The outfit operates on the principle of the oscillating spark as discovered by Albert I. Jahnke.
The principal feature of the outfit of course is the transmitter which while not explained in detail, was shown to have an automatic agitator to keep the carbon from packing. For tuning he has a conical helix, which can be connected up either as a helix or oscillation transformer permitting the outfit to work on either open or closed circuit "hook-ups."
He has six quenched spark gaps, which are operated at the unusually low tension of 40 to 53 volts across each gap. The spark gaps are operated under a special liquid, the formula of which is still secret.
Another feature, the details of which were not explained, is a variable condenser of remarkably high capacity, and small size; used to bring the spark in tune with the voice; it being explained that perfect coupling is necessary between the voice wave and spark wave, to produce the best results.
Up to date, the outfit has been operating at wave lengths below 3000 meters; but on phantom aerials in the laboratory, it has been found possible to operate successfully up to wave lengths as high as 20,000 meters.
Mr. Herrold claims for his system, the ability to radiate more energy than any system so far invented; and to show the remarkable efficiency of his system, he states, that the message received by the Bremerton Navy Yard, required only 1½ K.W. for the distance of 900 miles, which is certainly remarkable.
For receiving, he uses either the galena detector, or the audion; together with loose coupler, variable and fixed condenser and 3000 ohm receivers.
As to whether the transmitter was connected in primary or secondary circuits, and detailed hook-ups, etc., of course nothing was said, pending the further perfection of the outfit and system.
[Mr. Hymes is the sales manager of the E. I. Co. and is at present on a trip to the Pacific Coast.--Ed.]