QST/March 1916/Radio Communications by the Amateurs
Mr. C. D. Tuska.
Have received first two issues of “QST” and think they are great.
I recently came home after being on a six month’s trip on the S. S. Somerset (KSV) and I find that there have been numerous late developments in the “Amateur World,” some of which I know practically nothing about, for instance the Oscillating Audion, which I believe to be due largely to the co-operation of the amateur operators through the American Radio Relay League.
I find very few points on which to criticize the advanced amateur and his-work. One fault however, is that very little has been done to help the “Spark Coil Amateur” do long distance work. Many amateurs are unable to have current installed in their homes either because they live too far away from current wires or else they cannot afford the cost of installation. Cannot amateurs find some means by which long distance work with a spark coil may be improved? I have tried numerous experiments but can give only one suggestion for better work. That is: Place two bridges across the vibrator one bridge not to be connected to the vibrator or to the batteries but to be placed across the vibrator. By means of a thumb screw the note can be varied. This arrangement not only produces a high, pleasing note, but also increases the radiation.
Mr. R. M. McLain of Huntsville, Alabama, writes in part:
As I was passing through the lonely hills of North Alabama, several days ago, I noticed a young lady of about seventeen years standing on a barrel at the foot, of an aerial mast, repairing the aerial. I asked her what the trouble was and she explained that the wind blew down the mast every time she put it up. She had repaired it three times, in two weeks.
“Do you catch anything?” I asked.
“Oh, yes,” she replied, “I used to, but do not now. Do you know anything about fixing a detector?”
I examined the neat little set and found it O. K. I asked her if she liked the work.
“Oh, yes, I am crazy about it; I listen all the time.” I glanced about the yard and saw several mules and cows, a yard full of chickens, an old-fashioned spinning wheel, in perfect shape, and with thread on it. It looked as if the young lady could operate anything from an old spinning wheel to a modern wireless telegraph.
Mr. W. B. Pope, Athens, Georgia, writes:
I use a Packard one—quarter kilowatt transmitting set (transformer), balance of set of my own construction. I am in constant communication with Macon, Georgia, a distance of 100 miles from here. I have just received a letter from Mr. Charles W. Weber, Abington. Pennsylvania (about 10 miles north of Philadelphia) stating that he has been hearing me as loudly as he has been hearing a one kilowatt set located Within 200 miles of him.
In addition to a Packard one-quarter kilowatt transformer, I use three sections of Murdock moulded condenser, a high-speed rotary gap, giving almost 1,000 in terruptions per second, an oscillation transformer, glass insulator, of my own make, and wound with edgewise copper strip, and
an aerial only 75 feet high and 200 feet long, input to transformer, as when heard by above named party, three amperes.
This is one of the best records I have so far heard of, as the distance from Athens, Georgia, to Philadelphia. Pa., is between 700 and 800 miles. This was at 9:10 P. M. or there abouts and when conditions for wireless were not the best.
To the Editor “QST.”
In the various Armstrong circuits, is the increase in the strength of signals due entirely to the beat or heterodyne effect, or are there any other effects noticeable which cause added response in the phones?
If there were another type of generator, for undamped waves, as efficient as the audion, and if the beat effect produced by the generator were utilized on an ordinary detector circuit as sensitive as the ordinary audion receiver circuit. would this circuit be as sensitive and satisfactory as an Armstrong circuit?
What is meant by “increase in audibility”—an amplifier concern claims to have an instrument that increases the audibility 1500 times. Does this mean that the sound wave produced has 1500 times the amplitude and what relation has it to the number of times the signal strength is increased?
In the various Armstrong circuits, the increase in strength of signals is due to amplifying effect as in the ordinary amplifier rather than the heterodyne principle. Of course, in the Armstrong circuit, these two effects are combined, but the real increase is due to amplification.
It is the writer’s opinion that another type of generator such as you mention would not he as efficient as the Armstrong circuit. This is due to the peculiar repeating action which is obtained between the inductance coils.
“Increase in audibility” means that the instruments amplifies a given sound a certain number of times when a given factor of loudness is taken as the audibility unit. That is, a certain strength of signal may be taken with an audibility of one, then the amplification or increase in signal strength is a given number times the audibility.
A more complete discussion of these questions will he found in Armstrong’s article in “The Proceedings of The Institute of Radio Engineers,” Volume 3, No. 3.
My dear Mr. Tuska:
Allow me to thank you for your very courteous and carefully considered reply to my letter of the 22nd ult., regarding Armstrong circuits.
Not only have you answered my questions completely, but you have shown me the energy and seriousness of the work you
have undertaken. I am sure that the American Radio Relay League is and will be a great and thorough suceess—imitation and rival leagues notwithstanding.
Thanking you again, I am
Most sincerely yours,
(Signed) EDGAR FELIX.
NEW ROCHELLE RADIO CLUB
At a meeting held on Thursday night, Feb. 3, 1916, the amateur wireless operators of New Rochelle, N. Y. organized a club to he known as the Radio Club of New Rochelle. The purpose of this society is to better and further advance wireless telegraphy in New Rochelle. Of an initial membership of twenty the following officers were elected: President, John Bucknam, Vice President, Etienne Donovan, Secretary-Treasurer, Thomas Havard, and Press Agent, Edward Bettels.
The president appointed a committee whose duties it will be to establish and maintain a circulation library of the latest and best books on wireless, and the current magazines on the same subject. A second committee, the electrical, was appointed to take charge of the experimenting station of the club. This committee will perform its experiments before the members of the club.
FALL RIVER, MASS. HAS NEW CLUB
The “Fall River Amateur Wireless Association” has recently been formed. its object is to advance interest in wireless communication in Fall River and vicinity. The officers are: William H. Buffinton, President; Dana Hilliard, Vice—President and Harold C. Bowen, Secretary.
"PORTABLE AEROPLANE AND TRENCH RADIO SETS"
At the last meeting of the Radio Club of America, Mr. William Dubilier presented
a paper on “Portable Aeroplane and Trench Radio Sets” with special consideration of a type of apparatus developed by the author for utilizing direct currents in producing musical notes without the use of a motor generator set and revolving spark gaps. Mr. Dubilier has recently returned from France and England where he made experiments with these sets. He very interestingly described in detail, with lantern slides and apparatus, the installations now being used by the Allies for directing artillery fire, and communicating between trenches.
Mr. A. S. Blatterman presents very interesting paper before Institute of Radio Engineers.
At the meeting of the Institute of Radio Engineers, held Jan. 5th., a. paper on “Variations in Nocturnal Transmission” was presented by Mr. Blatterman. It gave a very interesting account of experiments in nocturnal transmission which have been carried on between the University of North Dakota and Washington University in St. Louis, Mo. A number of peculiar effects of value to experimenters in the radio field were quite clearly brought out.
The Club invites all amateur radio stations in the United States to communicate with them through their secretary, Thomas Havard, 48 John St., New Rochelle, N. Y.