Chapter 13:
Modulation and Transmitters
Objectives:
When the students have finished this chapter they should:
- be familiar with the different types of modulation used in Amateur
Radio
- be able to identify the various components of different
types of transmitters and their position relative to each other
Apparatus:
- HF receiver
- equipment to demonstrate digital modes
Handouts:
- Transmitter block
diagrams
Lesson Plan:
- Answer any questions about the Chapter 12 homework.
- The following road blocks make this a difficult to lesson to
teach with much student involvement:
- The Basic Qualification does not permit Amateurs with this
qualification to build a transmitter.
- Today's transceivers have no moving parts and it is difficult to
show your students much beyond printed circuit boards, integrated
circuits and a few RF transistors mounted on a big heat sink.
So perhaps the best tack here is to have them work together in small
groups, using the block
diagrams to learn what goes where and the function of each block. At
the same time they can work through the Chapter 13 Quiz
Questions.
- At the same time you can throw down the gauntlet, challenging them
to qualify later on down the road for Advanced Qualification, which
allows them to build transmitters. Show them plans for building
transmitters in the ARRL Handbook or in the various magazines that serve
the Amateur community. Check the Amateur community in your area to
determine who has done some "home brewing" of transmitters and ask them
to come along to the class to show off their efforts.
- Bring an HF transceiver or receiver to class. Arrange for two local
Amateurs to get on the air at a given time. Have one of them
deliberately "over modulate" so that your students can hear the
distortion. Then have the Amateur make the necessary adjustments so
that the distortion is eliminated. This is a variation on a picture
is worth a thousand words, although it is an 'audio picture' rather
than a visual one.
- Set up demonstrations of the various types of digital transmissions
RTTY, PACKET, APRS, and AMTOR
Homework:
- Read Chapter 13
- Learn the block diagrams "What goes Where"
- Do the Chapter 13 Quiz questions.
- Skim Chapter 14
Chapter 13 Quiz:
Printable copy of the Review
Quiz
Answers to Chapter 13 Quiz
1 |
A |
16 |
B |
31 |
D |
46 |
C |
61 |
D |
2 |
A |
17 |
B |
32 |
B |
47 |
A |
62 |
B |
3 |
C |
18 |
C |
33 |
B |
48 |
A |
63 |
C |
4 |
C |
19 |
C |
34 |
A |
49 |
A |
64 |
A |
5 |
C |
20 |
D |
35 |
B |
50 |
D |
65 |
D |
6 |
B |
21 |
A |
36 |
C |
51 |
D |
66 |
A |
7 |
B |
22 |
A |
37 |
D |
52 |
A |
67 |
D |
8 |
C |
23 |
C |
38 |
C |
53 |
D |
68 |
C |
9 |
B |
24 |
D |
39 |
D |
54 |
A |
69 |
B |
10 |
A |
25 |
B |
40 |
A |
55 |
C |
70 |
C |
11 |
C |
26 |
D |
41 |
D |
56 |
B |
71 |
D |
12 |
A |
27 |
B |
42 |
A |
57 |
B |
72 |
C |
13 |
B |
28 |
A |
43 |
D |
58 |
A |
73 |
D |
14 |
C |
29 |
D |
44 |
A |
59 |
B |
* |
* |
15 |
C |
30 |
A |
45 |
D |
60 |
C |
* |
* |
Overhead Slide Versions of the Diagrams
- Slide 1
13.1
Amplitude Modulation
13.2 Amplitude Modulation Spectrum
- Slide 2
13.3
Frequency Modulation