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,
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,
, Introduction to Number Systems and Logic Circuits, Introduction
to Microelectronics, Principles of Synchros, Servos, and Gyros
Introduction to Test Equipment
, Radar Principles,
The Technician's Handbook,
Master Glossary, Test Methods and Practices,
Introduction to Digital Computers,
Magnetic Recording, Introduction to Fiber Optics