NAEB Newsletter (Mar 1935)

- page 10 - Buxxetiii - , urc^ IT, E. STEWART, WCI ENGINEER GRINDS HIS OTJN CRYSTALS A gfeat step forward was nade in the frequency control of broadcasting stations with the advent of the crystal-controlled transmitter. '701, I believe, claims to have been one of the first transmitters in the middle west to take advantage of this ad¬ vance in the Radio arts. Crystal control brings problems of its own, however. One disadvantage has been the effect of tenperature on the crystal. A degree of change in the tenperature of the crystal is often enough'to throw the transmitter outside its allowed frequency deviation. To prevent this, the crystal is kept in an oven at constant temperature. In case of power failure, the oven may cool off and the trans¬ mitter must stay off, even after the power is back on, until the oven is warm again. The Bell system Technical Journal, July 1934, page 453, carried an article describ¬ ing a new way to cut the quartz plate so that no change in frequency results from a change in temperature. This cut has been named the "A-cut” crystal. This crystal is now on the market at a moderate price. However, rather than buy an ”A-cut” crys¬ tal, TfCI is giving its operators, who are students at Iowa State College, seme valuable experience and training by cutting and grinding an ”A-cut” crystal from the raw quartz. Incidentally, it gives the engineer an opportunity for some research along this line in which he is especially interested. Clarence E. Damon, 203 Administration Building, Purdue University, Lafayette, Ind. ; is responsible for the operation of station WBAA* According to the outline sub¬ mitted, they are making very effective use of the time at their disposal. Personally I am more interested in what they "are doing on their Children’s Hour, for the reason that at T70I we are now giving attention to this matter, I suspect that others will find other features that will appeal to them. I suggest that you write to 1 r* Damon for his program, if you do not now have it. Radio station WKAR of East Lansing, T ichigan, are broadcasting a series of lectures that are somewhat of an innovation. The series is called the Economics of the New Deal. If you are interested in this topic or other items on this program, I suggest that you write to Robert J. Coleman, director of TJKAR. William AcKinley Robinson is broadcasting programs representing Western State Teach¬ ers College at Kalamazoo, ".ichigan, over station WKZO. I am sure from the list of topics discussed that the time is being used to good advantage. Elmer G. Sulzer is responsible for the radio programs broadcast by the University of Kentucky over WHAS. ”In order to make available to the people of the mountains of Kentucky, University and other valuable radio features, a plan was inaugurated during the sprin c of 1933 whereby a system of Radio Listening Centers was to be es¬ tablished in this territory. In the carrying out of this system, the University of Kentucky equips such centers with radio sets, and the operators of the centers see that they are tuned daily to educational programs of worth. They encourage people of their communities to daily come in to the centers and listen.” Funds for the purchase of receiving sets in the listening centers were secured by donations. A fine series of children’s programs are being broadcast by station KOAC at Corvallis and by station KBPS, the station owned by the Benson Polytechnic School at Portland* If you are interested in the content of this program for the past three months, write to either one of the above mentioned stations. Station KFDY of Brookings, South Dakota, have a very effective way of releasing publicity. This is sent as page 4 of the literature known as 4-Ii Club Doings.