International projectionist (Jan 1943-Dec 1944)

V hy Your Motiograph Dealer Can Best Service ANY Equipment You don't have to own a Motiograph Mirrophonic Sound System or Motiograph Projectors to get the best guality service on your projectors, sound systems, lamps, generators, etc. Since your Motiograph dealer is not bound to any particular group of affiliated manufacturers but is free to sell all makes of eguipment, he is by experience better fitted to service EVERY type. Specializing in service, he is equipped with latest tools and machinery for doing every job quickly and with precision and efficiency. By actual personal experience he has become expert in the repair of all makes of equipment, not just one, and he has access to the repair departments of all the leading manufacturers. He is the owner of his business and as a fixture in your community he must live with his promises and his work. His success depends upon serving you satisfactorily. Impartial investigation reveals that the Motiograph dealer is always the best dealer in town because he has been selected as exclusive representative of the leading manufacturers. Do not hesitate to call him any hour of the day or night. MOTIOGRAPH ESTABLISHED 1896 4431 West Lake Street • Chicago. Illinois CLAYTON BALL-BEARING EVEN TENSION TAKE-UPS For all projectors and sound equipments All take-ups wind film on 2, 4 and 5 inch hub reels. Silent Chain Drives THE CLAYTON REWINDER For perfect rewinding on 2000-foot reels. CLAYTON PRODUCTS CO. 31-45 Tibbett Avenue New York, N. Y. AT YOUR SERVICE (Continued from page 13) Quick and Easy Method of Determining a Defective Tube In the event sound is lost in an amplifier and all tubes appear to have a lighted filament, an easy and quick way of determining which tube is defective is offered in the following methods which may be used on all types of amplifiers: 1. By touching the grid cap of high gain tubes with the hand and by holding the other hand in close proximity to an electric light bulb, or an unshielded light cord, an a.c. hum will be introduced in the amplifier output if that and succeeding tubes are functioning properly. 2. Another and sometimes easier method is to remove a tube from its socket, starting at the first tube and working back as it is replaced after removal. A sharp click or thump should be heard if all succeeding tubes are functioning. If the amplifier remains dead when the first tube is removed, pull and replace the second, the third, etc., until the thump is heard which indicates the succeeding tube is bad. This will work even for the output tube. — D. C. Ferguson, RCA. Cleaning W. E. Motors The seals of the Western Electric motors become very dirty in operation and should be cleaned regularly. Due to their construction, this is quite a job except when done with forced air. Generally a vacuum cleaner with an extension tube is used, but sufficient air pressure cannot be obtained through the resistance of the hose extension for a good job. By removing the hose and using the nozzle direct, the pressure is increased many times and all dirt can be blown out without taking down the motor. — P. N. Connet, RCA. Preventing Pad Roller Arm Damage In several instances breakage of pad roller arms and brackets was traced to a shift in position of the hold-back sprocket on the shaft. This was found due to an uneven cup rim on the set screw creating an impression that the set screw was seated properly. The shifting of the sprocket on the shaft caused jamming of the pad roller against the rim of the sprocket. All screws were carefully examined and those found in the above condition discarded and replaced by set screws with an even rim. Tightening of these set screws in the correct position of the sprocket on the shaft was achieved through positioning the sprocket while the pad roller was set down on the sprocket and used as a guide. Following this procedure no further breakages have occurred to date. —J. H. McGinley, RCA. • BUY WAR BONDS • 20 INTERNATIONAL PROJECTIONIST