Radio broadcast .. (1922-30)

What Our Readers Write Us 375 this note is to have you, if you please, tell Mr. Bouck when he returns that I have since been able to settle my difficulties quite satisfactorily by changing the tubes. I wonder if this suggestion is any good? Let RADIO BROADCAST offer to print the names of some fans in each of the large cities who have built say two or three Roberts outfits and are willing to share their experiences with others. The Roberts circuit is so good that unless you treat it right in construction, you'll have trouble. A few dont's from one who has done only to his sorrow, may save perplexities later on. This is offered for what you think it worth. Very sincerely yours, (Rev.) Robert E. Holland, S. J. What Doctor Pickard Thinks About Fading THERE have been many interesting arguments presented of late upon the effect of weather conditions upon radio transmission. Doctor Pickard, Consulting Engineer of the Wireless Apparatus Company of Boston, has made an intensive study of fading in transmission extending over a period of several years and which has brought out much valuable information. His most important work probably has been his study of the eclipse of the sun in January, 1925. His observations during the period of the eclipse were reviewed in a paper which was read before the Institute of Radio Engineers in April, and dealt rather conclusively with this very interesting subject. Doctor Pickard's reaction to Professor Van Cleef's article, which appeared in RADIO BROADCAST for May, is therefore, of especial interest. Mr. Van Cleef reviewed in his article the factors which influenced the transmission and reception of radio waves. There have been many theories put forth to explain the peculiar condition of fading. The most popular theory is, perhaps, that of the Heaviside Layer, which, in part, assumes that the various ionized layers of the upper atmosphere refract, absorb, or aid the waves in their passage. Doctor Pickard's letter follows: Editor, RADIO BROADCAST, Doubleday, Page & Company, Garden City, New York. SIR, I am indeed indebted to you for the galley-proof of Professor Van Cleef's interesting article. We certainly need the aid of the meteorologist in the correlation of weather and radio transmission. Few radio engineers who have specialized on transmission phenomena still retain the original or reflecting Heaviside Layer hypothesis. Not only did this hypothesis involve a grotesque amount and arrangement of atmospheric ionization, but to-day we realize that to act upon waves by conductivity would damp them out more rapidly than it would bend them. It is therefore refreshing to find a writer who pays no attention to the Heaviside Layer. For nearly a quarter of a century it has been recognized that those happenings below the isothermal layer, which we call weather, were related to radio transmission. Some five or six years ago a Frenchman, whose name has temporarily escaped me, made a very similar analysis to that of Professor Van Cleef, although he came to somewhat different conclusions. However, I do not share the author's assurance that reception conditions can be forecast with the same degree of accuracy as the weather, because I know several other factors profoundly affect transmission. But there is little that I can criticize in Professor Van Cleef's article. The principal factor in radio reception is not the electric field at the receiving point, because this can be discounted by increased amplification. The principal factor, is, however, the height of the disturbance level or noise background. The fact that winter reception is better than summer reception is really due to two things. First, there is less static or noise background, and second, there is less sunlight, and therefore less ionization of the lower levels of the atmosphere. Sincerely yours, GREENLEAF PICKARD. On Our Anniversary IT IS a pleasure to receive letters of the sort reproduced below. Such expressions make us feel that our earnest endeavors to present to the radio public a magazine of the highest grade have not been wasted. But our efforts for the last three years have not been confined to the dissemination of the best in radio alone. In November, 1923, RADIO BROADCAST inaugurated the first International Broadcast tests. The tests were repeated in 1924 as they will be in 1925, and the data obtained from these tests as well as in many other and different researches conducted by RADIO BROADCAST has been invaluable to the radio field. Mr. Rice is Manager of Broadcasting for the General Electric Company. GENERAL ELECTRIC COMPANY Editor, RADIO BROADCAST, Doubleday, Page & Company, Garden City, New York. SIR, In looking over the May issue of RADIO BROADCAST I find that it is an anniversary number. I congratulate you on the high grade and interesting magazine which you have edited for the past three years. Very truly yours, MARTIN P. RICE. Manager of Broadcasting.