A-005-01: Oscillator circuits, phase locked loop (PLL)
A-005-01-01:
How is the positive feedback coupled to the input in a Hartley oscillator?
Through a tapped coil
Through a capacitive divider
Through link coupling
Through a neutralizing capacitor
A-005-01-02:
How is positive feedback coupled to the input in a Colpitts oscillator?
Through a capacitive divider
Through a tapped coil
Through a neutralizing capacitor
Through a link coupling
A-005-01-03:
How is positive feedback coupled to the input in a Pierce oscillator?
Through capacitive coupling
Through a neutralizing capacitor
Through link coupling
Through a tapped coil
A-005-01-04:
Why is the Colpitts oscillator circuit commonly used in a VFO?
It is stable
It can be used with or without crystal lock-in
The frequency is a linear function with load impedance
It has high output power
A-005-01-05:
Why must a very stable reference oscillator be used as part of a phase-locked loop (PLL) frequency synthesizer?
Any phase variations in the reference oscillator signal will produce phase noise in the synthesizer output
Any phase variations in the reference oscillator signal will produce harmonic distortion in the modulating signal
Any amplitude variations in the reference oscillator signal will prevent the loop from changing frequency
Any amplitude variations in the reference oscillator signal will prevent the loop from locking to the desired signal
A-005-01-06:
Positive feedback from a capacitive divider indicates the oscillator type is:
Colpitts
Pierce
Hartley
Miller
A-005-01-07:
In an oscillator circuit designed for high stability, the positive feedback is drawn from two capacitors connected in series. These two capacitors would most likely be:
silver mica
ceramic
electrolytics
mylar
A-005-01-08:
In an oscillator circuit where positive feedback is obtained through a single capacitor in series with the crystal, the type of oscillator is:
Pierce
Colpitts
Hartley
Miller
A-005-01-09:
A circuit depending on positive feedback for its operation would be a:
variable-frequency oscillator
mixer
detector
audio amplifier
A-005-01-10:
An apparatus with an oscillator and a class C amplifier would be:
a two-stage CW transmitter
a fixed-frequency single-sideband transmitter
a two-stage frequency-modulated transmitter
a two-stage regenerative receiver
A-005-01-11:
In an oscillator where positive feedback is provided through a capacitor in series with a crystal, that type of oscillator is a:
Pierce
Colpitts
Hartley
Franklin
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