To the center of the trace the receiver tuning can be changed and the

Cathode Ray Tube Diagram

Amount by which it must be changed to bring the peak to the center indicates how far off the receiver calibration is. Referring back to Fig. 447, the peak was brought to the center by changing the receiver tuning from 600 kc. to 595 kc. This means that the receiver calibration at 600 kc. is off by 5 kc. It should be clearly understood that the optimum adjustment is attained when the r-f. and detector stages are tuned to the incoming signal and the oscillator frequency is higher than the signal...

Around a glass cylinder

In order to facilitate observation or to simplify the pattern, it is frequently desirable to separate the front and rear patterns. In other words, patterns, such as we have shown, can be said to have front and rear portions, which are on the same horizontal plane. That is why, under certain phase conditions, certain peaks or loops are covered by Fig. 120. This circuit is used for separating the front and rear portions of a pattern, making the interpretation of high ratio figures much simpler....

Alignment Of Tuned Circuits

The alignment of a tuned circuit, so as to establish the correct resonant state by visual observation, is commonly understood to be the most valuable application of the cathode-ray oscillograph. Having read through this volume up to this point, you no doubt appreciate our statement when we say that observation of resonant circuits is but one more application of the cathode-ray instrument we are discussing. It is true, however, that, from the viewpoint of the servicing industry, it is an...

L

Schematic diagram of a beat frequency oscillator which is frequency modulated by the motor driven variable condenser in the lower left corner of the diagram. This type of oscillator, when frequency modulated, provides a band width that is constant for any output frequency. In contrast to the single oscillator type of frequency modulated source of test signal, there is in use the dual oscillator system, operated with a motor driven frequency modulator condenser, whereby a constant band...

The Deflection of the Beam

There are two important functions performed in the cathode-ray tube oscillograph. The first is the focusing of the electron stream into a narrow concentrated beam of electrons. The second is the placement of this beam under the influence of an electric or magnetic, or combination of both, types of field, in order to secure the proper deflection of the beam. Deflection of the beam results in a pattern or image visible upon the fluorescent viewing screen, which pattern furnishes the information...

Jvw

Fig. 229-A, left, Fig. 229-B, middle, Fig. 229-C, right. A. The wave envelope of the modulated output of a commercial test oscillator. B. The a-f. output of the same oscillator. C. The a-f. signal resulting from demodulation of the modulated wave shown in A. Concerning modulated wave patterns, the design of the majority of commercial service test oscillators, with possibly one or two exceptions, is such that the modulated waveform varies with the frequency setting of the test oscillator....

Focusing the RCA Type Cathode Ray Tube

Let us now associate figure 5 with the electrodes used in the RCA type cathode-ray tube and see how closely the optical analogy of focusing is like the electrical means employed in the tube. Examine figure 6. H is the heater. C is the cathode, which is the electron emitter and equivalent to the light source. G is the control grid and is the equivalent of the light gate, or stop S. Just why this is so will be stated later. Anode Al is the equivalent of lens O and anode A2 is the equivalent of...

Transformer windings which is related to the starting winding This

Non Synchronous Vibrator

Winding shunts one half of the primary winding in all full wave, synchronous and non-synchronous vibrator systems. The oscillograms we shall show will serve to illustrate how the cathode-ray oscillograph can be used to establish the effect of various adjustments, showing that various changes in adjustment and circuit constants influence the voltage waveform and proper interpretation should lead to most efficient servicing. The schematic wiring diagram of the full-wave non-synchronous vibrator...

Table Of Contents

What the Cathode-ray Tube is and What it will do 1. Types of Cathode-ray Tubes 2. What is in the Cathode-ray Tube 6. The Western Electric 224 Tube 7. The RCA 906 Tube 8. How the Cathode-ray Tube Works 10. Optical Analogy of Focusing 11. Focusing the RCA type Tube 14. Focusing in Other types of Tubes 17. Magnetic Focusing 19. Beam Deflection 20. Tubes with No Plates or One Pair 20. Beam Deflection in Different types of Tubes 21. Spot Positioning 30....

O

The schematic diagram of the RCA Model TMV-122-B cathode-ray oscillograph. NOTE C-21 not included on all instruments. cerned, the instrument consists of a type 885 grid controlled gas triode, which is in effect a thyratron, as the saw-tooth wave-time axis oscillator, two individual resistance-capacity coupled amplifiers, a two-tube rectifying system, one tube functioning as a full-wave rectifier supplying the plate and grid voltages for the two amplifiers and the other tube functioning as a...

Index

See Resonance Curves at wrong frequency, 269 Automatic Frequency Control, 332 circuit connections, 260, 266 incorrect band width, 269, 271 insufficient band pass, 271 rectification for visual, 257 requirements for correct, 261 600 kc., 320 Amplifier See Resonance Curves calibration of oscillograph gain controls, 176, 177 checking audio overload of, 188, 189, 190, 191, 192, 193 checking Class B, 201, 202, 203, 204 checking frequency response of, 280-286, 315 checking Class C See Transmitter...

Clough Brengle Model 210 Rf Signal Generetor

The schematic diagram of the Clough-Brengle Model OM frequency modulated r-f. oscillator. The 76 tube in the middle of the diagram is the constant frequency oscillator that is frequency modulated by the motor driven condenser at the left. be used with any r-f. oscillator of suitable frequency range required to cover all operating bands. The Clough-Brengle OM frequency modulated r-f. oscillator is shown in figure 278. The type 76 tube nearest the 6A7 mixer is the variable band...

Persistency of Vision

At this time it is imperative to bring one pertinent fact to your attention. You have read repeated references to SPOT positions. While these may have appeared repetitive and perhaps superfluous, the frequent references were premeditated. We want to impress upon you that the electron beam causes a fluorescent spot to appear upon the screen at the point where the beam strikes the screen. Irrespective of the nature of the voltage impressed upon the deflecting plates, it is only a single spot...

Appendix

Reference is made on pages 216 and 217 to testing mixer systems for distortion. This can be done by using the tuned amplifier mentioned in this volume. The signal from the test oscillator is fed through the amplifier to the cathode-ray tube and the character of the modulated wave is observed. This can be done at frequencies as high as several megacycles, providing that the modulated carrier signal is fed directly to the vertical deflection plates, without passing through the vertical deflection...

Dotted line and the position of the spot upon the screen is When

The difference of potential previously described exists between the plates, the beam is pulled out of line as it passes between the plates and the spot upon the screen is moved to the point indicated by the number 1, the beam being shown as a dotted line. The extent that the spot is moved up away from its normal position, or the extent of the pull upon the beam towards the upper plate DP-1, is determined by the preponderance of the positive charge upon this plate, with respect to plate DP-2. If...