Lesson 7: Signals and Emissions
Signals and emissions cover how modulation and digital modes shape a signal and its bandwidth.
What you will learn
- G8A Carriers and modulation: AM, FM, and single sideband; modulation envelope; digital modulation; overmodulation; link budgets and link margins
- G8B Frequency changing; bandwidths of various modes; deviation; intermodulation
- G8C Digital emission modes
1. Read
- Operating on HF: Which sideband to useHelps with G8A
- Digital modes: FT8 and FT4Helps with G8C
- Digital modes: PSK31 and RTTYHelps with G8C
- Digital modes: Digital voiceHelps with G8C
- Digital modes: The rules for dataHelps with G8C
- All 42 G8 questions with their answers and explanationsEvery group, with the rule or source behind each answer
2. Explore
- Decibels
Add gains and subtract losses in decibels to build a simple link budget: transmitter power, feed line loss and antenna gain.
3. Practice
Practice one group at a time. A group is ready when you have answered every one of its questions and learned at least 80 percent of them; a question counts as learned when your last three answers to it were correct. To review quickly, go through this lesson’s questions as flashcards.
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