Module 8—Introduction to Amplifiers
Pages i - ix
1-1 to 1-10
, 1-11 to 1-20
1-21 to 1-30
, 1-31 to 1-40
2-1 to 2-10
, 2-11 to 2-20
2-21 to 2-30
, 2-31 to 2-35
3-1 to 3-10
,3-11 to 3-20
3-21 to 3-30
, 3-31 to 3-40
3-41 to 3-50
, 3-51 to 3-60
3-61 to 3-70
, AI-1 to AI-3
is accomplished by using both series and shunt peaking.
LOW-FREQUENCY COMPENSATION is accomplished in a video amplifier by the use of a
parallel RC circuit in series with the load resistor.
A RADIO-FREQUENCY (RF) AMPLIFIER uses FREQUENCY-DETERMINING NETWORKS
the required response at a given frequency.
The FREQUENCY-DETERMINING NETWORK in an RF amplifier provides maximum impedance at the
desired frequency. It is a parallel LC circuit which is called a TUNED CIRCUIT
TRANSFORMER COUPLING is the most common form of coupling in RF amplifiers. This
coupling is accomplished by the use of RF transformers as part of the frequency-determining network for the
ADEQUATE BANDPASS is accomplished by optimum coupling in the RF transformer or by the
use of a SWAMPING RESISTOR.
NEUTRALIZATION in an RF amplifier provides feedback (usually
positive) to overcome the effects caused by the base-to-collector interelectrode capacitance.
ANSWERS TO QUESTIONS Q1. THROUGH Q42.
A-1. The difference between the upper and lower frequency limits of an amplifier.
A-2. The half-power points of a frequency-response curve. The upper and lower limits of the band f
frequencies for which the amplifier is most effective.
A-3. (A) f2 = 80 kHz, f1 = 30 kHz, BW = 50
kHz (B) f2 = 4 kHz, f1 = 2 kHz, BW = 2 kHz
A-4. The capacitance and inductance of the circuit and
the interelectrode capacitance of the transistor.
A-5. Negative (degenerative) feedback.
A-6. It decreases.
A-7. It increases.
A-8. The capacitance of the circuit.
A-9. Peaking coils.
A-10. The relationship of the components to the output-signal path.
A-11. Combination peaking.
A-12. The coupling capacitor (C3).
A-13. A shunt peaking coil for Q2.
A-14. A decoupling capacitor for the effects of R2.
A-15. A part of the low-frequency compensation network for Q1.
A-16. A series peaking coil for Q1.
A-17. A swamping resistor for L2.
A-18. L1, L2, and R5.
A-19. R9 and C5.
A-20. The gain increases.
A-21. The gain decreases.
A-22. To provide maximum impedance at the desired frequency.
A-24. By changing the value.
A-25. Transformer coupling.
uses fewer components than capacitive coupling and can provide an increase in gain.
A-27. A step-down
A-28. A too-narrow bandpass.
A-29. By using an optimally-coupled transformer.
A-30. Low gain at the center frequency.
A-31. A swamping resistor in parallel with the tuned circuit.
A-32. RF transformers are used and
the transistor is neutralized.
A-33. Degenerative or negative.
A-34. By neutralization such as the use of a capacitor to provide regenerative (positive) feedback.
A-35. C2 and the secondary of T1.
A-36. R1 provides the proper bias to the base of Q1 from VBB.
A-37. R2 provides the proper bias to the emitter of Q1.
A-38. The output would decrease. (C4
decouples R2 preventing degenerative feedback from R2.)
A-39. C5 and the primary of T2.
A-41. The dotted lines indicate that these capacitors are "ganged" and are tuned together with a
A-42. C3 provides neutralization for Q1.
Introduction to Matter, Energy, and Direct Current, Introduction
to Alternating Current and Transformers, Introduction to Circuit Protection,
Control, and Measurement, Introduction to Electrical Conductors, Wiring Techniques,
and Schematic Reading, Introduction to Generators and Motors,
Introduction to Electronic Emission, Tubes, and Power Supplies,
Introduction to Solid-State Devices and Power Supplies,
Introduction to Amplifiers, Introduction to
Wave-Generation and Wave-Shaping Circuits, Introduction to Wave Propagation, Transmission
Lines, and Antennas, Microwave Principles,
Modulation Principles, Introduction to Number Systems and Logic Circuits, Introduction
to Microelectronics, Principles of Synchros, Servos, and Gyros,
Introduction to Test Equipment, Radio-Frequency
Communications Principles, Radar Principles, The Technician's Handbook,
Master Glossary, Test Methods and Practices, Introduction to Digital Computers,
Magnetic Recording, Introduction to Fiber Optics