Projection engineering (Sept 1929-Nov 1930)

Page 48 Projection Engineering, September, 1929 HOUGH AUTOMATIC HORN LIFT The Earl B. Hough Co. of Chicago, Illinois, makers of the Hough Organ Lift, announce a new automatic sound picture horn lift. The problem of what to do with horns while a stage act was on was only partially solved with the introduction of movable horn towers which permitted the rolling-off of the horns into the wings. The one objection of these towers was that they required much valuable stage space. The Hough horn lift is installed under the stage floor and is operated automatically much in the same fashion as is an organ lift. The horn lift is contained with in a ceiling height of 8 feet below the stage and has an upward travel of 15 feet or more, as required. It is powered by a 1% horsepower motor, driving a cable consuming drum through a ball-bearing steel and bronze worm gearing and operates in a dust-proof oil bath. The raising or lowering operation, which is silent, requires 45 seconds. The lift is operated from a push-button located on the stage switchboard, with the lift, when traveling either up or down, stopping automatically at the predetermined end of travel. The National Theatre Supply Co. will furnish full details of this unit. NEW PACENT EQUIPMENT Full details on the two new Pacent Junior models for houses up to 500 seats were released recently by the Pacent Reproducer Corporation. Pacent, in issuing the statement, promised the small exhibitor machines which deliver the highest quality and performance. The new machines combine a number of new features. There are two new Pacent models for houses up to 500 seats. The Type 500 DDA is for synchronous disc reproduction, and sells for $1,500. It has full doublechannel amplification with a reserve amplifier for every amplifier used to run a show. No batteries are used in the operation of the system. The amplifiers operate direct from any 110-volt, 60-cycle a-c. source. Other features found in the new Junior model 500 DDA are constant speed motors, mechanical gear drive, and a new type of pickup which tracks all records perfectly and has a remarkable coverage of the frequency range. The latest type of dynamic speaker is used in both the new Pacent models. This type of speaker, especially developed for small theatres, is said to give unusual power, with a large reserve to bring out the full effect of all programs. The second of the new Pacent machines is known as the Type 500 FDA. It combines synchronous disc and sound on film reproduction. The price of this model, for houses up to 500 seats is $2,500 for both disc and sound on film. The features of the disc system are the same as those for the Type 500 DDA disc system, including full double-channel amplification, new type pickup and mechanical gear drive. The sound-on-film section of the new Type 500 FDA combines several new and highly interesting features. Both the variable area and variable density methods are played with equal efficiency. The sound-on-film section is extremely simple to operate, due to special designed features. When disc is played it is not necessary to thread through the sound-on-film section. A specially designed optical system is employed, which with the special photoelectric cell gives the highest quality of reproduction by the sound-on-film method. A new feature in sound-on film section is found in the periscope through which the projectionist makes a complete, quick check on sound-on-film operation. The two Pacent models Type 2 MDA and TYPE 4 MDA for houses up to 4,000 seats are continued as regular items. No nrice change in these models has been made and none is contemplated according to the Pacent Corporation. PRESTO RECORDING MACHINE The salient feature of the Presto Recording Machine is its vibrationless construction accomplished through the simple expedient of a belt drive separating the power unit from the recording head. By this simple and at the same time thoroughly mechanical construction th« need of expensive filtering devices so necessary in geared constructions — and at best inefficient — is at once eliminated and there is provided a smooth, even, perfectly regular transmission to the recording head by which the slightest vestige of vibration is eliminated at the essential point. The machine is available for regular recording at 80 r. p. m. or 33 1/3 r. p. m. for synchronized picture work. The change over is practically instantaneous. The belt drive for synchronized work is of such design and construction as to insure positively the established ratio and to maintain such ratio under any and all conditions. In fact, the construction is such as to make the machine almost universal inasmuch as any desired feed can be made available by the simple substitution of a pulley on the recording end. A vital constructional feature is the turntable tapered bearing which is self-aligning and automatically adjustable to wear without the need of end-thrust take-up. The bearing is a fit when made, remains a fit and there is no possibility of any play developing. A convenient feature is a simple cam means for establishing a positive cutting starting point. The cutter point is dropped on the wax at the desired starting point and the simple operation of setting a stop against the cam face automatically produces the starting groove and the feed then proceeds at the predetermined rate. For straight recording a hand lever operation cuts the spiral groove at the end of the record. A play-back is provided on the feed slide whereby immediate testing can be made without removing or disturbing the cutter head, means being provided for engaging or disengaging either the cutter or the play-back. The machine is designed and built on the unit-construction plan, is portable in the most practicable sense and is of precision specifications to a degree that insures per fect cutting for both straight and synchronized recording work. The machine is the latest development of the Presto Machine Products Co., 70 Washington St., Brooklyn, N. Y., which concern has specialized in the production of sound reproducing devices for the past thirteen years. SIMPLIFIED TELEVISION SCANNER ANNOUNCED An ingenious combination of scanning drum and selector shutter has just been demonstrated by the Jenkins Television Corporation engineers. The new arrangement, which takes the place of the Jenkins scanning drum with light-conducting rods and four-plate neon glow lamp, is far simpler, cheaper and more efficient in matters of detail and illumination. In fact, not only are the silhouette or Jenkins radiomovies received with crisp, sharp, sparkling black-and-pink definition, but halftone pictures are also handled by the same scanning mechanism with excellent results. With experimental transmissions of a close-up film of a girl by the Jenkins W2XCR station, the new scanning mechanism can reproduce the animated pictures with sufficient detail so that the features are readily identified by the lookers-in. There is also a considerable increase in illumination, due to the use of a standard neon lamp with large plates, instead of the former small plates of the four-plate neon lamp. With the elimination of the revolving contact switch gear for flashing the multiple plates in proper turn, the present mechanism presents a minimum of noise in operation. The main point about this new Jenkins development, however, is that a scanner can be produced at a relatively low cost. With the elimination of the elaborate scanning drum with light-conducting rods and multiple-plate neon lamp, the equipment is reduced to simplest and most economical terms, yet the performance is remarkably improved. The use of a novel selector shutter in combination with a small scanning drum, so that the drum rotates four times in flashing each 48-line picture, results in retaining the compact dimensions for which the Jenkins technique is noted. Cam for Starting Line fSf < ' ' / mV^Feed Nut Lever Synchronous Motor 33 Vz R.P.M. For 80 R.P.M. Recording Use Round Belt— Perforated^ Belt for Synchronizf m Cam era '^Work Explanatory illustration of the Presto recording machine.