Radio today (Apr-Dec 1939)

Smite ticks win a satisfied customer, because panel lamp life is unpredictable and the old one you leave in the socket may expire just after you've reinstalled the chassis in the cabinet." (Continued from page 31) Framing Control — A control for centering the picture. Focusing Control — A control on the receiver to bring out definition; it actually controls the width and sharpness of the individual lines on the cathode-ray tube. Focusing (.Action) — This is the action of the gun of the cathode-ray tube which concentrates the stream of electrons to a small spot. (This can be accomplished by either electrostatic or magnetic methods.) Ghost — An unwanted image in the picture which is usually caused by signal reflection. Gun (Cathode Ray)— The structure or mount inside the cathode-ray tube that produces, accelerates and focuses the electron beam. Horizontal Tearout — This term describes the breaking up of the upper part of the picture, either to the right or left. The cause is usually poor low frequency response in the sweep circuits or video amplifier. Interlacing — This refers to the technique of dividing the frame into two fields with displaced lines to eliminate flicker. Interaction — A term usually used by designers indicating leakage or the mixing of a signal into another circuit. Line — A single line of the 441 comprising the television picture. Linearity — Means uniform rate of motion. This is required as the picture will be distorted in non-linear portions. Modulation — A process of applying the video signal to the modulating or control electrode (or grid) of . a cathode-ray tube so as to produce the lights or shadows of a picture. Paraphase — A term used in television and English books which is equivalent to the American "push pull." Phasmajector — A tube for generating television picture signals. Reflectors — Additional rod or rods placed near the antenna to reinforce signals. Sawtooth — A saw shaped wave of electric current or voltage employed to scan or sweep a cathode-ray tube. Scanning — (See Sweep.) Separator — The circuit used to separate the horizontal and vertical synchronizing pulses from each other and the video signal. Spot — A visible spot of light formed by the impact of the electron beam upon the screen. Sweep — The action of an electron beam in tracing lines across the screen. Synchronization — A process of producing synchronism between circuits. Television — A general term for the transmission or reproduction of visual images by radio. Teletron — A receiving cathode-ray tube. Video — Pertaining to the picture section of the receiver or transmitter. Rep/ace panel lamps "Make complete replacement of all receiver panel lamps at one time when the customer's set is being serviced," Hygrade Sylvania Corp. urges servicemen. "You'll make extra profit and Arvin 9A auto receiver The Arvin 9-A auto receiver utilizes a rather conventional 6-tube superhet circuit. A pentode R-F amplifier is used to provide increased sensitivity and image selectivity. Dual purpose tubes are employed in the first and second detector circuits. I.F. alignment takes place at 170 KC. Location of high-frequency trimmers shown on chassis layout with proper frequencies for alignment. High-voltage circuits shown in accompanying diagram in extra heavy lines. Arrowheads indicate signal path through set. Tuning indicator types consolidated Because of the great similarity among several of the types of tuning indicator tubes, it has been decided to discontinue some of the less popular types in cases where these older types are directly interchangeable with some of the newer, more popular types. The original tuning indicator tube was type 6E5 which consisted of a cathode ray tuning indicator section combined in one bulb with a sharp cutoff triode amplifier section. Soon after this, the type 6G5 was introduced. This type was similar to the type 6E5 except that the amplifier section has a remote cutoff or variable mu characteristic so that the tuning indicator could be more conveniently used in sets employing variable mu ARVIN MODEL 9~A F. PEAK 170 KC