.. BULLETIN OF BROADCASTING,-. I STATIONS I IN THIS rssue HEW BROADCASTING STATEOM LOG NEW LIST OF ALL NORTH AYERICAIU BROADCASTING STATIONS CHART OF AIR LINE DISTANCES BETWEEN CITIES OPERATING TIME OF BROADCASnNG STATIONS STEVENSON'S BULLETIN OF RADIO BROADCASTING STATIONS Published Quarterly by NATIONAL PUBLISHING COMPANY - 1220 H Street N. W., Washington, D. C. THOMAS STEVENSON, Editor W. W. RAPLEY. Treasurer and Business Manager RICHAItD bl. NASH, Circulation Manager PETER BECIIER, JR, Advertising Mgr. Volume 4 DECEMBER, 1927 Kumber 2 CONTENTS Page Fading May Be Calculated in Advance 3 Station Heterodynes Spoil Distant Programs ------------------ 4 Coast-to-coast Reception of Programs Expected ------------- 5 Heterodynes Might Have Been Prevented ..................... 6 Advertisers Responsible for Program Quality------------------ 7 Television May Be Achieved Soon ........................ 8 Radio Law Does Not Authorize Station Reduction ---------------- 9 New Sense Being Developed by Radio Listeners --------------- , 10 Radio Beacons Contribute to Airplane Safety------------------ 11 List of American Broadcasting Stations...................... 12 List of Canadian Broadcasting Stations...................... 30 List of Cuban Broadcasting Stations...................... l-- 32 List of Mexican Broadcasting Stations....................... 32 Other North American Broadcasting Stations------------------ 32 Air Line Distances ............................... 33 '. Operating Hour of American Broadcasters--- --------------- 38 Location of North American Broadcasting Stations-----------~ 42 Poor Reception Caused by Imperfect Antenna ----------------- 47 Calibration of Set Increases Efficiency------------------ ---- 48 Stevenson's Broadcasting Log------------------------------- 49 -. STEVENSON'S BULLETIN OF RADIO BROADCASTING STATIONS is pub- lished quarterly. Publication clates are September, December, March and June. The subscription price is $1.00 per year. A11 sul~scriptionsare paynble in advance. Unless otherwise clirected, new subucri1)Lions \rill begin with current issue. When changing an ad(lress, give tho old a(1tlress ns well as the new. Entered.as Second Class mntter at the Postoi3ice at Washington, D. C., under the Act of March 3, 1879. (Copyright 1927 by Natlonal Publishing Company) Fading ESTS by Bureau Stevenson's ACH issue con- of stadr* E tains list of all Radio Laboratory North American reveal a degree of Broadcasting s t a - May be regularity in fading Provides tions; air line mile- for any particular age chart, broad- place; use of high casting station log Calculated power does not af- Complete and editorial review fect characterktics of outstanding radio of fading. Service developments. in Advance IGHER power by broadcast- readily distinguishable kinds of OULD you like to receive revised Broadcasting Station Log ing stations does not affect fading, a fairly slow and a rela- regulai-ly a corrected with all Federal Radio Commission H the characteristics of fad- tively rapid fluctuation. w Broadcasting Station changes, in addition to these fea- ing, although the signals sent out There is a regular kind of fad- Log which would enable you to: tures : with higher power do not so fre- ing which sometimes occurs during quently fall below audibility, re- the 45 minutes just following sun- cent tests by the U. S. Bureau of set. Determine at a glance which-sta- An air mileage chart giving dis- Standards Radio Laboratory re- Fading is not connected with tions you should be able to get with tances between principal cities of veaL weather conditions in any way, so your radio receiver; the United States. Fading is the frequent bane to far as could be learned, nor is it reception of distant programs. The similar at two receiving points program will come in strong, then Determine at a glance just where Operating hours or time on the close together, nor for the same gradually fade out, later coming in these stations should come in on air of the larger broadcasting sta- station at different times. strong again. Scientists are try- your dials. tions. This last fact proves that the ing to find a way to counteract cause of fading is not associated fading. with the transmitting or receiving This is exactly what you can do An alphabetical list of places in There is a degree of regularity locality, and that it must, there- with the Broadcasting Log which North America having broadcast- in fading not hitherto suspected. fore, be in the medium between. begins on Page 49 of this issue of ing stations. The average night fading for any This leads to a theory which ex- particular place apparently can be plains fading and which is being STEVENSON'S. And on Page 48 Ec9 you are told how to do it. predetermined, even though the widely accepted and used to ex- Editorial summary of important fading varies from instant to in- plain other phenomena viz, day- developments in the broadcasting stant in wholly erratic fashion. light propagation of radio waves STEVENSON'S is published field with a review of activities of Fading is at its worst about 60 along the earth, and nighttime quarterly. Each issue contains a the Federal Radio Commission. to 126 miles from a broadcasting propagation along ' the Kennelly- station; at greater distances it di- Heaviside layer, free from ground minishes, but then increases again absorption. with distance and has repeated According to this theory, fading ON SALE AT ALL NEWS STANDS- maximums and minimums for is due to irregular absorption in $1.00 THE YEAR BY SUBSCRIPTION greater distances. There are two the ionized upper atmosphere. Distant Programs RESENT wave HAIRMAN of P length mssgn- C Federal Radio ments by Federal Commieeion predicts Spoiled by R a d i o Commission wave length ehan- reepomible for whie- nela gradually will t2es which impair be clm~edof htero- program quulity for dyning and interfer- Station dktant listeners; too ence so that pro- many broadcasting grants mybe heard stations k the cause. from Atlantic to Heterodynes Expected Paci@. of over 500 watts without the AVE length assignments By WILLIAMH. G. BULLARD proper distance separation. by the Federal Radio Chairman, Fe'dera2 Radio Commission Commission are resulting Heterodyning is the result. in stations heterodyning each Within a certain radius of the sta- ROADCASTING STATIONS best type of long distance recep- other. tion, the volume is sufficient to are rendering and will con- tion. When a broadcasting station overcome the whistles of other B tinue to render many dif- This process is one for normal sends out a program, there is a stations using the same wave. But ferent types of service. Some of growth, not for arbitrary rulings. certain area around the station at a distance from the station the them, although primarily engaged As stations themselves develop within which it can be received. program is spoiled because the I in giving dependable program serv- their program service in the public But beyond the area where recep- signals are too weak to offset the ice within their normally effective interest, and their mechanical tion of the program is possible, whistles. radius of a hundred miles or so, equipment with power adequate there is a whistle or beat-note. When radio regulation was in are able under favorable condi- for the best transmission of these Most listeners know of cases the Department of Commerce, tions to reach far afield. programs, the roads are being when they are able te get the broadcasting channels were divided It is to such great stations, cleared for them. whistle of a station without being into two bands-A and B. with their high power and highly The Commission is looking for- able to bring in its program. This Class B wave lengths, or the developed program service, that ward to the time when the listener, whistle extends far beyond the band between 280 and 545 meters, the long-distance listener turns, on any night of good reception, area where the program can be were assigned to high grade sta- and because long-distance listen- can hear broadcasting stations received. tions. Class A wave lengths, or ing is a vitally important part of from the Atlantic to the Pacific, Radio engiaeers say that be- the band between 200 and 280 radio reception, it is essential that from Canada to Mexico, without cause of the whistle, it is inadvis- meters, were assigned to second such stations should be as free as interference, on channels cleared able to assign the same wave grade stations. possible from the interference for them, not by arbitrary rulings length to broadcasting stations of Duplication of waves was not caused by heterodyning. of the Government, not by fixed over 600 watts power for simul- permitted in the class B band, ex- One by one the frequencies used and necessarily discriminating taneous operation unless they are cept when the stations were sepa- by such stations are actually being classifications, but by the normal, thousands of miles apart. rated by the entire country. In the cleared, not simply by action on logical qrocess of demonstrated To accommodate nearly 700 class A band, many stations were the part of the Commission, but by fitness and capacity to render a broadcasting stations on 90 wave assigned the same wave for simul- the'fact that smaller stations have great public service. lengths, the Commission assigned taneous operation and their power no desire to create ill-will for Such a development is entirely kept low to avoid interference. the same wave length to stations themselves by interfering with the (Please