Long Lines, April, 1922, pages 30-31:
TELEPHONING TO SEA
Another Development In Radio Communication.
ON the evening of Sunday, March 5, at about 7:30 o'clock, President Thayer was called to the telephone at his residence in New Canaan, Conn., to answer a call from Captain Rind on his ship, the "America," then approaching New York, but still 24 hours from port.
"Hello, this is Captain Rind."
"Captain, this is Mr. Thayer of the telephone company. I'm up in New Canaan. I understand you are three or four hundred miles at sea."
"Yes, we were 370 miles from Ambrose Light at 7:30. We expect to dock tomorrow evening at 7 or 8."
"What kind of a trip are you having?"
"We're having a good trip for this time of the year."
"Well, I'm glad to have had the pleasure of speaking to you. I think it is fine that we can meet and talk this way."
That, with the usual parting greetings, was the conversation. As the Bell engineers explained to those who listened in from a vantage point in New York, it means that the time is undoubtedly coming when there will be nothing strange in any telephone subscriber from Seattle to Havana lifting his receiver and talking to a friend on one of the large trans-oceanic ships of the Atlantic or Pacific fleet. This demonstration of ship-to-shore telephony, quite impromptu in its character, was given to about a dozen newspaper men and it left with all present the impression that the wireless telephone in conjunction with the land lines is destined eventually to play a most important part in ship-to-shore communication. Those who witnessed the demonstration were gathered on the 24th floor of the Walker-Lispenard building in which are located the operating and test rooms for all the long distance lines entering New York.
Preliminary to her last voyage to Europe, the steamship "America" had been equipped by the Radio Corporation with a wireless telephone set of General Electric Company manufacture. Throughout the eastward trip tests were carried out between the ship and the radio telephone station of the Bell System at Deal Beach, N. J. These tests were overheard night after night by radio amateurs in the neighborhood of New York and led to many questions concerning their purpose.
The evening of March 5 was selected as the time for a demonstration because the ship was scheduled to be then between 350 and 400 miles from port--a fair working range under normal atmospheric conditions for the radio sets both on the ship and at Deal Beach. The time was well chosen, for with the exception of 10 or 15 minutes during which the wireless waves were subject to "fading," telephoning between the ship and shore proceeded without the slightest difficulty.
From the diagram the reader will note that two separate stations were used on the Jersey Coast, Deal Beach being the transmitting station and Elberon the receiving station. Those who are informed on technical matters will note that the wire circuit was operated on the 4-wire principle between Walker Street and the radio stations, and on the ordinary 2-wire principle from Walker Street to New Canaan. A hybrid coil and balancing network, such as forms an essential part of all telephone repeaters, established the union between the 2- and 4-wire circuits.
The demonstration, while it brought out the possibilities of ship-to-shore communication, also illustrated its shortcomings--shortcomings which are, in a large measure, characteristic of radio in all forms. At irregular intervals throughout the test, which lasted for over an hour, intelligible communication with the ship was entirely prevented by interference from spark stations most of which were on vessels at sea, the spark stations near New York having very generously stopped their sending. The elimination of interference between stations, all engaged in carrying commercial business, is one of the important technical problems of radio still awaiting solution.
Another limitation of the wireless telephone was forcibly brought out by the number of telephone calls which came in from persons who said they had little radio sets in their homes and were listening in. However, improvements in the direction of secrecy may be expected and the Bell engineers have already done much to eliminate this shortcoming.
Moreover, atmospheric conditions exert a marked influence upon the ease with which a radio message travels through the ether. These conditions vary greatly from day to day and from hour to hour. This can be well illustrated by the observations which have been made in connection with the Bell wireless telephone operating between Los Angeles and Catalina. The distance between the mainland and the island is 30 miles and the sets have been made sufficiently powerful to transmit speech across this distance under the most unfavorable conditions. On the other hand, it has been found that this amount of power is sufficient under exceptionally favorable conditions to make these messages readily audible in New Zealand, 5,000 miles away.
Another atmospheric phenomenon which is a source of most serious disturbance to wireless transmission and which thus far has baffled all attempts to eliminate it, is the so-called "static." Fortunately for the demonstration we have just described, there was very little static present.
