Broadcasting (Jan-June 1933)

MARK WARNOW, who has conducted and played for a variety of musical programs during his four years on radio, has been appointed staff musical director of CBS in New York. "DANCING In The Dawn" is the name of a new waltz recently written by B. G. Carpenter and arranged by George Kelly, production manager of ,WDEL, Wilmington, Del. LESLIE ADAMS, chief announcer of KMTR, Hollywood, has been promoted to production manager. Dean Metcalf, formerly of KFWI, San Francisco, has gone to KMTR as announcer. IN THE CONTROL ROOM REOPENING of the frequency monitoring station of the Chicago radio inspection office of the Radio Commission, which was shut down about three months ago, is contemplated about July 1, or as soon as an adequate location can be selected. The Commission also is preparing to close the monitoring station at Larkspur, Cal., operated by the San Francisco inspection office, effective July 1. FORBES VAN WHY, chief technician at KMTR, Hollywood, has been appointed a lieutenant (senior grade) in the U. S. N. R. as executive officer of section 1, eleventh naval district. KMTR has added two operators — Alvon C. Packard, formerly communications engineer for the Mutual Telephone Co., Honolulu, and Don C. Good, lately in consulting work in San Diego for shipping interests. COLLAPSING in the midst of a broadcast he was handling, George Lewis, engineer of WCAU, Philadelphia, was rushed to a hospital May 20 only after he had "seen the program through" and was operated on for appendicitis. He is reported recovering. 'CONCENTRATOR' ANTENNA PROVED Results oi KYW Operation Highly Satisfactory After Six Months, Westinghouse Reports SIX MONTHS of operation with the "concentrator" antenna developed for KYW, Chicago, by Westinghouse E. & M. Co., which owns the station, have proved the efficacy of this latest innovation in radiating systems, according to an announcement by Westinghouse May 27. Results obtained in increased coverage, it is claimed, have more than exceeded the highest expectations, since the signal strength of the station was nearly doubled in the heavily populated centers in and around Chicago. The antenna, in effect, consists of two vertical radiators, so spaced and properly adjusted in such a manner as to concentrate the larger portion of the radiated energy in the directed direction. The unique feature of this installation, Westinghouse states, was the utilization of wooden masts for the support of the conductors which radiate the 10 kw. on KYW's 1020 kc. frequency. Westinghouse Report A DETAILED semi-technical explanation of the development of the antenna and how it functions, was made public by Westinghouse as follows: The main antenna at KYW, generally referred to as the exciter antenna, consists of a wooden mast which supports a section of copper tubing 204 feet in length. When first installed, an attempt was made to work "IN THE HEART OF THE EAST" MASON DIXON RADIO GROUP WORK— York, Penna. WGAL — Lancaster, Penna WDEL— Wilmington, DeL WAZL — Hazleton, Penna. This industrial and agricultural area of over 5,000,000 people with more than 450,000 radio sets is covered throughout the major portion of the day and night by the Mason-Dixon stations with intelligent, entertaining and instructive programs. Modern equipment for handling electrical transcriptions available. Flat rate — national or local advertisers. For rate cards and group booklet Address All Inquiries to MASON DIXON RADIO GROUP C. R. McColIough, Gen. Mgr., Lancaster, Penna. WORM'S EYE VIEW— The KYW concentrated antenna as it appears from the ground. "Exciter" coil is heart of new radiator system. the antenna as a half-wave radiator. A tuning coil was placed midway between the top and bottom of the pole and at a height of about 100 feet, and current fed by means of a two-wire transmission system to the transmitter. This particular system presented some difficulty in the matter of tuning and adjustments and after some experiments were made it was decided that a quarter-wave, under the circumstances would be more feasible. Since Jan. 5, 1933, the exciter antenna has been worked as a quarterwave, its advantages over the halfwave being that it is little affected by weather conditions and can be tuned and adjusted at the base of the mast. Also as the present method of operating the quarter-wave antenna makes use of a ground consisting of copper sheets and radial wires, the wood pole is very nearly at the same potential as the antenna itself, thus doing away with the possibility of loading considerable portion of the radiated energy into the supporting mast. Extra Guys Used WHEN the antenna was first installed, three sets of guys, consisting of four guy wires each, were made use of to hold the mast erect. The top most set of guys was approximately 140 feet above ground. There remained, unsupported, a 60 foot section of the mast at the top. It was decided that this presented a hazard in the case of high winds or ice collecting, and an additional set of guys was installed and attached to the mast, approximately 175 feet from the ground. All guy wires had been insulated from the ground and the pole by means of insulators and were broken up into 40 foot sections. The installation of the latter set of guys dropped the signal strength approximately 5 per cent. More insulators were then installed in this set of guy wires, breaking the sections up into 20 feet lengths. Later, additional insulators were installed on the portion of the guy wires that were in proximity to the antenna. The signal strength then returned to its normal value. Since then, a few extra insulators have been installed in guy wires on the second set, with a slight improvement in field strength resulting. Weathered Gale KYW's new antenna since its installation has weathered a 50-mile gale without damage and the effect of ice. On March 18, 1933, a heavy coating of ice formed on the antenna. Signal strength dropped approximately 10 per cent. The reason for this was not ascertainable until one of the top guy wires burned off, due to an arc caused by radio frequency leaking across the ice from the copper tubing to the guy wire. It was noticed that even though the guy wire had dropped, an arc still held between the short section still attached to the pole and the copper tubing. By vigorously shaking one of the guy wires on the top section, the ice at this point was dislodged and the signal strength immediately returned to normal, although the remainder of the pole and copper tubing was still entirely covered with ice. Since then, additional insulators have been installed as close to the pole as possible, thus eliminating a considerable amount of coupling to the wires that are attached to the pole itself. Previously the first or top insulator was placed 24 inches from the pole. It is believed no more trouble from this source will be encountered. Single-Wire Feeder THE LEAD-IN on KYW's former antenna was located in such a manner as to be inductively coupled to the 500 ohm transmission line termination in the tuning house. Upon erection of the new antenna, which was located 120 feet from the tuning house, it became necessary to install another transmission line from this tuning house to the new antenna. At the present time, the new antenna is being fed by a single-wire feeder, connected at a point about 50 feet above the ground and inductively coupled to the transmission line termination in the tuning house. The reflector portion of the new antenna system differs somewhat in construction from the exciter antenna for reasons of economy rather than necessity. It consists of one single wooden mast, extending 90 feet above ground and on top of which is attached a fabricated 60-foot duralumin tower. The convention copper tubing attaches to this mast and extends down the length of the wood pole to an inductance which tunes this installation to 1020 kc. This mast is guyed with a single set of four guy wires and although the fabricated tower portion of this antenna, due to its nature, collects a considerable load of ice, no mechanical or electrical difficulties were encountered. Relief Order Extended EXTENSION to Nov. 1 of the order relaxing the terms of the radio regulations requiring stations to operate a minimum of two-thirds of their authorized hours was authox-ized by the Radio Commission May 23. Under the action, stations may reduce operating hours upon written application. The modification was adopted by the Commission originally last March because of the economic situation and numerous requests from stations for relief. Amateur Proposals WIDENING of the amateur radiotelephone assignment to 1800-2000 kc, a new allocation of 28,00028,500 kc, and a proposal that only pure direct current power supplies be permitted in amateur stations, were urged upon the Federal Radio Commission by the directors of the American Radio Relay League May 12 at their annual session in Hartford, Conn. The annual central division convention of the league will be held at the Century of Progress Exposition, Chicago, Aug. 3, 4 and 5. Page 22 BROADCASTING • June 1, 1933