Ham Radio General Class Practice Test

Which of the following is an advantage of a transceiver controlled by a direct digital synthesizer (DDS)?

1. Wide tuning range and no need for band switching

2. Relatively high power output

3. Relatively low power consumption

4. Variable frequency with the stability of a crystal oscillator

The correct answer is: Variable frequency with the stability of a crystal oscillator

A transceiver controlled by a direct digital synthesizer (DDS) offers variable frequency synthesis while maintaining the stability typically associated with a crystal oscillator. This is a significant advantage because it allows for precise frequency changes without sacrificing the quality and accuracy provided by a crystal's frequency stability. DDS technology utilizes digital signal processing techniques to create high-frequency signals, which can be adjusted in very fine increments. This flexibility enables operators to efficiently tune across a wide range of frequencies. Additionally, the stability of crystal oscillators ensures that the output frequency remains consistent over time and with changes in temperature, enhancing overall reliability for communications. While wide tuning ranges, power output, and power consumption are important considerations in radio transceivers, they do not specifically highlight the unique capability of DDS systems compared to conventional approaches. Hence, the key advantage here is the ability to achieve variable frequency operation combined with the rock-solid stability of crystal oscillators.