International projectionist (Jan-Dec 1954)

nature of the trouble. If the iron is rated for 1000 watts, your pencil and paper will give you the answer quickly, using Ohm's Law. Repairing electric toasters, and table lamps offer another source of sideline income. Record Players You probably own a record player and you know from your own experience that sooner or later it will need attention. The manual type is very simple; the changer type is complex, particularly the three-speed variety. You should obtain servicing instructions for the changer in question and Best Wishes for a Happy and Prosperous 1954 to all our Friends from PROJECTIONISTS LOCAL NO. 128 Boston, Mass. a most satisfactory income may be delivered from the repair of these machines. Sound Projectors In addition to portable sound pro cepted. Placing your finger on the grid cap of the first stage tube in the amplifier will result in a buzz in the speaker, if the amplifier is OK. Portable sound movie systems are Study them. The illustrations that are jectors, the tape recorder is also be very tough and can take a lot of abuse. I included with the instructions will en able you to grasp the sequence of operations and will give you a better understanding of the mechanism. Your skill also includes the knowledge of circuits as used in your own theatre amplifiers. Many portable record changers with their own sound systems require frequent attention because the heat is contained within the cases. This heat destroys the lubricating qualities of grease and oil, turning them into sticky, gummy layers and interfering with the automatic operation of the machine. This is a very lucrative source of side-income, but you must know your stuff and give quick and efficient service. The skill of the projectionist in handling film and projectors stands him in good stead in the 16 and 8-mm fields. The narrow gauge films are widely used now, especially in the educational and industrial fields, and coming very popular in non-professional application. Both types of equipment are operated quite often by relatively unskilled persons and are bound to require attention by an experienced person sooner or later. Many projectionists own their own 16-mm equipment and profit by renting it out, with themselves handling the shows. In checking portable projection systems, your procedure is much the same as with standard machines in the projection room except that some special stunts may be necessary. When testing for sound, for example, use a piece of thin paper to interrupt the x-lite beam. This is so that you can see the light, if it is present. This would not be possible with a thick card and your conclusions might be incorrect. With the volume control advanced, power on, you should get a plunk in the speaker when the x-lite beam is inter MAYBE THE UNITED NATIONS CAN SETTLE THIS THING? By Louis Sumien, member of Local 640, Nassau & Suffolk Counties, N. Y. 22 An extra PEC and x-lite are usually carried with each set-up. Exciter lamp failure is often due to a defective oscillator coil. Here your ohmmeter tells the story quickly — whether it is an open, short, or ground. If you are in a position to do this sort of work, you should obtain schematics for several makes and study them. The thing that owners appreciate is resourcefulness in making the equipment operate by substitutes. Thus an x-lite in a portable movie system can be supplied with current from batteries appropriately wired to give the required pressure and paired off to give heavy current. In a pinch you can use a 50L6 output transformer as a step-down transformer to light the x-lite, but here will you run into a noticeable hum since a PEC has a high sensitivity to frequency change. Radio Repairs Radio repair work requires somewhat extensive equipment in the way of oscillators, tube testers, and analyzers. Custom sound installing does not require any great number of tools and the projectionist usually has the background needed for this work. Such work involves selecting an amplifier, a record player, and a speaker. Where a stereophonic or binaural effect is desired, a speaker system is necessary. Home decorating magazines provide good ideas on custom installations that can be "sold" to prospective customers. Part of your equipment is your "caddy." This is a baggage type case with compartments in which you carry tubes, phono cartridges, a clean rag, extension cords, and other tools. A test meter, soldering iron, and socket wrenches are indispensable tools. (Continued on page 26) INTERNATIONAL PROJECTIONIST • JANUARY 1954 I