Module 8 − Introduction to Amplifiers
and Direct Current
||Alternating Current and Transformers
||Circuit Protection, Control, and Measurement
||Electrical Conductors, Wiring Techniques,
and Schematic Reading
||Generators and Motors
||Electronic Emission, Tubes, and Power Supplies
||Solid-State Devices and Power Supplies
||Wave-Generation and Wave-Shaping Circuits
||Wave Propagation, Transmission Lines, and
||Introduction to Number Systems and Logic Circuits
||- Introduction to Microelectronics
||Principles of Synchros, Servos, and Gyros
||Introduction to Test Equipment
||Radio-Frequency Communications Principles
||The Technician's Handbook, Master Glossary
||Test Methods and Practices
||Introduction to Digital Computers
||Introduction to Fiber Optics
|Note: Navy Electricity and Electronics Training
Series (NEETS) content is U.S. Navy property in the public domain.
Combination Peaking 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
to provide 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 amplifier.
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
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.
A-26. It uses fewer components than capacitive coupling and can provide
an increase in gain.
A-27. a step-down transformer.
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 single control.
A-42. C3 provides neutralization for Q1.