VERSATILITY—The Dyna-Jet Model 747 tube tester checks over 99% of all vacuum tubes in general use in television receivers, radios, and audio equipment. Over 2500 tube types are listed in the tube chart. FAST “JET-CHECK” TESTING —Most of the popular television and radio tubes can be checked on the “Jet-Check” section, which requires setting only the HEATER and SENSITIVITY controls before testing can begin. PROGRAMMED TESTING—All tube types which cannot be tested in the “Jet-Check” section can be given the same type tests in a separate programmed section. A program switch for each pin of the tube sets up the test circuit. Such programmed testing means the instrument is obsolescence proof; all new tube types that are introduced can be tested. DYNAMIC TESTING—Amplifying tubes in either the “Jet-Check” or programmed section are given a true dynamic mutual conductance (Cm) test. Diodes and rectifiers are tested for emission. Test results are reliable, even for High voltage regulators. A large, easy-to-read BAD—?—GOOD meter displays the test results. HIGH VOLTAGE REGULATORS-A special dynamic test has been designed into the Model 747 to properly test high voltage regulator tubes with proper plate current. Some competitive testers destroy tubes with a high current emission test, while others test with insufficient current which results in all tubes testing good. This special dynamic test injects a signal voltage to the grid and another much higher voltage applied to the plate. After extensive set testing and circuit design we now have a test that separates the good tubes from the bad. SHORTS TEST —A single pushbutton shorts test checks shorts or leakage between elements. Leakage paths up to 1 megohm will light the SHORTS lamp, and leakage as low as i/2 microampere can be detected on the meter. GRID EMISSION TEST—A single pushbutton test checks gas, grid emission, or grid-to-cathode leakage by a sensitive grid current check. Grid leakage paths of 100 megohms can be easily detected on the meter. LIFE TEST—A single slide switch checks life expectancy by dropping heater and operating voltages 10% to determine the tube's reserve capacity. DUAL SECTION TUBE TESTING—Each section of a dual section tube is tested separately. Therefore, tubes with identical sections can be checked and selected for balance between sections. This is convenient for selecting dual section tubes to be used in push-pull circuits. TUBE CHART—The tube chart is an integral part of the tester. It lists all set-up instructions for testing each tube type. Pages are indexed for ease and speed in locating tube types. Over 2500 listings cover nearly all tube types available. Additions are published regulary to add the newest tube types. VOLTAGE REGULATED—Compensation for line voltage variations gives highly reliable test readings at all times. PORTABILITY—The rugged, easy to carry case, which is made of molded plastic, allows the tester to be carried into the home on service calls, or used on the bench. PIN STRAIGHTENERS—Five built-in pin straighteners accommodate all tube types with flexible pins.