Book 3 Flashcards
What are the Three types of Single Side Band?
- Suppressed Carrier Single Side Band (SCSSB)
- Pilot Carrier Single Side Band (PCSSB)
- Controller Carrier Single Side Band (CCSSB)
What is a Suppressed Carrier Single Sideband?
No carrier is transmitted, only the selected Sideband.
What is a Pilot Carrier Single Sideband?
Transmits a small carrier at 1/40th of the normal power.
What is a Controlled Carrier Single Sideband?
Transmit either the Sideband or the full power carrier, during pauses in speech.
What are the advantages of Single Sideband?
- More power efficient
- Half the bandwidth
- Less Noise
- Less Distortion
What is the disadvantage of Single Sideband?
The receiver has to generate the carrier signal accurately to prevent distortion of the audio.
What is the purpose of the Balanced Modulator?
Mixed F1 and F2 signals to produce the LSB and USB, whilst eliminating the carrier
What is the purpose of the Crystal Filter?
To pass the selected Sideband.
What is the purpose of the Balanced Mixer?
To mix the Sideband signals with the output of the HF Oscillator to produce the desired output frequency.
What is the purpose of the HF Oscillator?
To provide a range of frequencies between 3MHz and 30MHz, allowing the required output channel to be selected.
What is the purpose of the Mixer?
Changes the RF to IF
What is the purpose of the Audio Detector?
Mixed the carrier and Sideband signals to allow the original audio to be recovered.
Changes the RF signal to AF signal
What is Deviation?
A measure of how much the carrier frequency varies either side of the reference frequency.
How is Deviation modulated?
Through the amplitude of the modulating signal voltage.
What is the Rate of Deviation?
How fast the signal frequency varies from its normal frequency.
