International projectionist (Jan 1963-June 1965)

Dealers fjr the Strong Electric Corp., Toledo, Ohio in attendance of the Allied-Tesma-Teda convention and trade show heard a discussion of the market potential for blnvn type arc projection lamps by Arthur J. Hatch, Strong's president. Cliff Callender, Strong's sales manager of the theatre equipment division, detailed the favorable experience with Xenon projector lamps as encountered at the World's Fair. A newly developed Xenon slide projector was also described. Dealers attending the meeting were: left to right, seated, Vm Geissler, Wil-Kin Inc., Atlanta; Bob Tankersley, Western Service & Supply, Inc., Denver, Colo.; Bob Wolfe, San Francisco; J. W. McBurnie, Charleston Theatre Supply Co., Charleston, W. Va.; H. J. Ringold, Ringold Theatre Equip ment Co., Grand Rapids, Mich.; Carl White, Quality Theatre Supply Co., Omaha, Neb.; and Dick Sutton, Des Moines The are Equipment Co., Des Moines, Iowa. Left to right, standing, are Cliff Callender, Strong Electric Corp., Toledo, Ohio; Arthur J. Hatch, Strong Electri: Corp., Toledo, Ohio; W. L. Waterhouse, General Sound & Theatre Equipment, Ltd., Toronto, Ont.; Howie Forbes, Theatre Equipment Co., Detroit, Mich.; John J. Kenny, Theatre Equipment Co., Detroit, Mich.; Floyd C. Pearson, General Sound & Theatre Equipment, Ltd., Toronto, Ont.; Phil Wicker, Standard Theatre Supply Co., Greensboro, N. C; Armand Besse, Besse Theatre Supply Reg'e., Montreal, Canada; L. M. Wutke, Pembrex Theatre Supply Corp., Los Angeles; and Bill White, Strong Electric Corp., Toledo, Ohio. i film will have to be used t<> obtain correct lateral adjustment. Replace exciters if the glass envelopes have blackened or if the filaments are Been to sag. Adjust exciters up and down and sideways for maximum light on the photocell cathodes. Be sure exciters are tight in their sockets— the\ draw a heavy current at low voltage. Adjustment of optical-tube fo us and azimuth i rotational adjustment) is a \ei\ critical matter, and is properly left to the service engineer v ho will use his frequency test films ; nd output meters. In an emergercy, however, thread up a film bavin; a lot of high-frequenc) sound — mnny fine lines across the track. Draw ibis down through the scanning beam very, very slowly b\ means of the handwheel, and observe the flickering shadow patterns on the photocell cathode. If the shadow bands move up on the photocell: the optical tube is too close to the film: if they move down, the tube is loo far away. Adjust the position of the tube l without disturbing the azimuth I so that the shadows of the soundtrack striations flicker uniformly on the photocell cathode, moving neither up nor down as the film is drawn International Projectionist Jan through the scanning point very slowl) . Check film tension in magnetic soundheads and demagnetize all filmcontacting parts ol the entire projector with a "degaussing" electromagnet energized In 60-cycle AC. Casehardened aluminum alien sprockets offer no magnetization problems. The outputs of the soundheads on both projectors should be equalized in the preamplifiers. We must emphasize once again that sound adjustments should be made b) a trained sound-service engineer, not by the operating projectionist in the normal course of events. D. OPTICAL LINEUP AND AND SPEAKER CHECK 1. OPTICAL LINEUP Test the projector optical train for alignment. This must be perfect, especially in light-hungry drive-ins. Stop up the automatic fire shutters and remove the lenses from the mechanisms. Sight through each machine l using a pocket mirror if necessary I or stretch a string tightly from the center-hole of the lamp mirror to the middle of the lens holder. uary. 1965 I his is the "optical axis." The centers of lamp mirror, positive carbon holder, film aperture, and lens holder must all be in a straight line. The lamp mirrors should be positioned at the recommended "working distances'" from the film apertures. and the lens holders must support the projection lenses square to the apertures, and without looseness or vibration. Regulate arc current for normal burning of the carbon trim used, and correct any abnormal conditions in the rectifiers or in the generators and their ballast rheostats. After it gets dark enough to project light on the screen, adjust the arc-lamp mirrors and carbon burners for maximum light properlycentered. ( Run the projectors, but without film for these adjustments.) 2. MOTORS AND PROJECTOR SHUTTERS Check the pickup times of both projector motors. They should be the same, and bring the machines up to normal running speed in 2 or 3 seconds. Pickup time can be adjusted in split-phase induction motors by means of the starting-winding rheo 13