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117 Cards in this Set
- Front
- Back
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What is the purpose of a sine wave oscillator? |
Convert DC Energy to sinusoidal AC Energy. |
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What is the purpose of a Hartley Oscillator? |
Convert DC Energy to sinusoidal AC Energy. |
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What is the purpose of a colpitts oscillator? |
Convert DC Energy to sinusoidal AC Energy. |
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What is the purpose of a RC phase shift oscillator? |
Convert DC Energy to sinusoidal AC Energy. |
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What is the purpose of a crystal oscillator? |
Convert DC Energy to sinusoidal AC energy. |
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What is the purpose of a sawtooth generator? |
Convert square wave energy to a sawtooth waveform. |
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The FET is a ___________. |
Unipolar Device |
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The element that current carries enter the FET through is called? |
Source |
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The element that current carriers leave through is called? |
Drain |
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The flow of current carriers through the FET is controlled by this element. |
Gate |
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What is the most common fault in a FET amplifier? |
A failed semiconductor component. |
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What is it called when current flow remains constant? |
Saturation |
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What are the 4 steps to troubleshoot an amplifier? |
1. Determine amplifier operation 2. Determine if Vcc is present 3. Determine if FET is good 4. Isolate problem to bias circuit |
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How is a Hartley Oscillator identified? |
They have two inductors in the feedback circuit. |
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How is frequency determined in a Hartley Oscillators? |
The values of the components in the feedback circuit determine the frequency. |
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How is a colpitts oscillator identified? |
Two capacitors in the feedback circuit. |
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How is frequency determined in a colpitts oscillator? |
Frequency is determined by the components in the feedback circuit. |
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How is an RC Phase Shift oscillator identified? |
They have three RC networks in the feedback circuit. |
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What is the total phase shift in an RC Phase shift oscillator? |
360 degrees. Q1 is a common emitter amplifier that produces a 180 degree phase shift. Each RC network produces a phase shift as well. |
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How is frequency determined with the sawtooth oscillator? |
The frequency of the output is determined by the frequency of the input. |
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What is the purpose of a blocking oscillator? |
They change DC into short, rectangular pulses that can be used as timing pulses to trigger other circuits. |
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Blocking Oscillator |
Any oscillator that cuts off its own oscillations at a predetermined time. |
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Transconductance (gm) |
The amount of control that the input voltage has over the output current.
Gm= Ioutput/Einput |
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What is the purpose of a blocking oscillator? |
To produce sharp, narrow timing pulse. A blocking oscillator cuts of its own oscillations at a predetermined time. |
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What is the purpose of a sawtooth generator? |
To convert square wave energy to a sawtooth waveform. |
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Name the 3 multivibrators whose purpose is to convert DC Energy to square wave energy. |
1. Astable Multivibrator 2. Monostable Multivibrator 3. Bistable Multivibrator |
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Converts DC energy to square wave energy |
Astable Multivibrator |
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Converts DC energy to square wave energy |
Monostable Multivibrator |
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Converts DC energy to square wave energy |
Bistable Multivibrator |
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What type of blocking oscillator is a monostable Multivibrator? |
Trigger |
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How is the output frequency determined in a bistable Multivibrator? |
The output frequency is one half the input trigger frequency. |
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What is the purpose of a Schmitt trigger? |
To convert any input waveform of any shape and amplitude into square wave pulses of constant amplitude. |
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In a Schmitt Trigger when is output high; when is output low? |
The output is high anytime the input exceeds the threshold.
The output is low anytime the input signal is below the threshold. |
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All FET biasing techniques accomplish two things: |
1. Place a positive voltage on the drain to establish current flow.
2. Reverse bias the source to gate PN junction to control current flow. |
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The action of converting detected intelligence into sound waves that a human can hear. |
Reproduction |
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Detection |
The action of separating the low frequency intelligence from the high frequency carrier. |
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The ability of the receiver to isolate one station's frequency from the many frequencies present at the antenna. |
Selection |
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Reception |
Occurs when a transmitted electromagnetic wave passes through the receiver's antenna. |
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Which is the most widely used FET? |
Common Source |
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What is Calculated Av? |
Gm*Rd |
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What are common gate FET normally used as? |
Switch |
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What are Common Source and Common Drain FETs normally used for? |
Amplifiers |
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Forward biased measurements indicate what? |
Normal resistance reading is low. A high reading indicates an Open FET. |
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Reversed biased measurements indicate what? |
Normal resistance measurement is high. A low reading indicates a shorted FET. |
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With the diode test function, how many directions should current flow? |
One |
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What is it called when current flow remains constant? |
Saturation |
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What are the 4 steps to troubleshoot an amplifier? |
1. Determine amplifier operation 2. Determine if Vcc is present 3. Determine if FET is good 4. Isolate problem to bias circuit |
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How is a Hartley Oscillator identified? |
They have two inductors in the feedback circuit. |
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How is frequency determined in a Hartley Oscillators? |
The values of the components in the feedback circuit determine the frequency. |
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How is a colpitts oscillator identified? |
Two capacitors in the feedback circuit. |
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How is frequency determined in a colpitts oscillator? |
Frequency is determined by the components in the feedback circuit. |
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How is an RC Phase Shift oscillator identified? |
They have three RC networks in the feedback circuit. |
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What is the total phase shift in an RC Phase shift oscillator? |
360 degrees. Q1 is a common emitter amplifier that produces a 180 degree phase shift. Each RC network produces a phase shift as well. |
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How is frequency determined with the sawtooth oscillator? |
The frequency of the output is determined by the frequency of the input. |
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What is the purpose of a blocking oscillator? |
They change DC into short, rectangular pulses that can be used as timing pulses to trigger other circuits. |
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Blocking Oscillator |
Any oscillator that cuts off its own oscillations at a predetermined time. |
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Transconductance (gm) |
The amount of control that the input voltage has over the output current.
Gm= Ioutput/Einput |
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What is the purpose of a blocking oscillator? |
To produce sharp, narrow timing pulse. A blocking oscillator cuts of its own oscillations at a predetermined time. |
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What is the purpose of a sawtooth generator? |
To convert square wave energy to a sawtooth waveform. |
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Name the 3 multivibrators whose purpose is to convert DC Energy to square wave energy. |
1. Astable Multivibrator 2. Monostable Multivibrator 3. Bistable Multivibrator |
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Converts DC energy to square wave energy |
Astable Multivibrator |
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Converts DC energy to square wave energy |
Monostable Multivibrator |
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Converts DC energy to square wave energy |
Bistable Multivibrator |
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What type of blocking oscillator is a monostable Multivibrator? |
Trigger |
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How is the output frequency determined in a bistable Multivibrator? |
The output frequency is one half the input trigger frequency. |
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What is the purpose of a Schmitt trigger? |
To convert any input waveform of any shape and amplitude into square wave pulses of constant amplitude. |
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In a Schmitt Trigger when is output high; when is output low? |
The output is high anytime the input exceeds the threshold.
The output is low anytime the input signal is below the threshold. |
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All FET biasing techniques accomplish two things: |
1. Place a positive voltage on the drain to establish current flow.
2. Reverse bias the source to gate PN junction to control current flow. |
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The action of converting detected intelligence into sound waves that a human can hear. |
Reproduction |
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Detection |
The action of separating the low frequency intelligence from the high frequency carrier. |
|
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The ability of the receiver to isolate one station's frequency from the many frequencies present at the antenna. |
Selection |
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Reception |
Occurs when a transmitted electromagnetic wave passes through the receiver's antenna. |
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What are AM receivers? What does the AM broadcast band cover? |
AM receivers are electronic devices that pick up signals sent from AM transmitters. Frequencies go from 535 KHz to 1605 KHz |
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Which is the most widely used FET? |
Common Source |
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What is Calculated Av? |
Gm*Rd |
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What are common gate FET normally used as? |
Switch |
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What are Common Source and Common Drain FETs normally used for? |
Amplifiers |
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Forward biased measurements indicate what? |
Normal resistance reading is low. A high reading indicates an Open FET. |
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Reversed biased measurements indicate what? |
Normal resistance measurement is high. A low reading indicates a shorted FET. |
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With the diode test function, how many directions should current flow? |
One |
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What is Amplitude Modulation? |
Occurs when the carrier frequency is altered in the amplitude by the lower intelligence frequency. |
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How many circuits do the turner block contain? What does each one do? |
Tuner contains 3 circuits. RF Amplifier- selects and amplifies one frequency from the many picked up by the antenna. Local Oscillator- produces a frequency 455 KHz above the selected RF. Mixer- produces four frequencies |
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What is LO, RF, LO+RF, and LO-RF? |
LO Frequency- 455 KHz LO+RF- Adds 455 KHz to the RF. RF- Given number LO-RF- is also referred to as the intermediate frequency (IF). |
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The transistors in a Multivibrator are biased so.... |
That they are either in cutoff or saturation. |
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The transistors in a Multivibrator are biased so.... |
That they are either in cutoff or saturation. |
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When a transistor in a Multivibrator is ON, it's output voltage is ________. |
LOW |
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The transistors in a Multivibrator are biased so.... |
That they are either in cutoff or saturation. |
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When a transistor in a Multivibrator is ON, it's output voltage is ________. |
LOW |
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In a Multivibrator, what is meant by a transistor being on? |
The transistor is in saturation. |
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The transistors in a Multivibrator are biased so.... |
That they are either in cutoff or saturation. |
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When a transistor in a Multivibrator is ON, it's output voltage is ________. |
LOW |
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In a Multivibrator, what is meant by a transistor being on? |
The transistor is in saturation. |
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Free running Multivibrators generate a square wave output.... |
Anytime the operating voltage is applied. |
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The transistors in a Multivibrator are biased so.... |
That they are either in cutoff or saturation. |
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When a transistor in a Multivibrator is ON, it's output voltage is ________. |
LOW |
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In a Multivibrator, what is meant by a transistor being on? |
The transistor is in saturation. |
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Free running Multivibrators generate a square wave output.... |
Anytime the operating voltage is applied. |
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In an astable Multivibrator, what determines which transistor turns ON when power is first applied? |
The transistor that conducts first. |
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What type of operation does a monostable Multivibrator use? |
Triggered |
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What is the frequency of any monostable Multivibrator? |
The same as the input |
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What is the frequency of any monostable Multivibrator? |
The same as the input |
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The frequency of an monostable Multivibrator is determined by____________. |
The input trigger frequency |
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Most faults in Multivibrators result in.... |
Either no output or a Vcc level on the output |
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A Schmitt trigger produces a high output only when __________. |
The upper threshold level is exceeded. |
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A Schmitt trigger produces a high output only when __________. |
The upper threshold level is exceeded. |
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Schmitt triggers are also called ___________. |
Squaring amplifiers |
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A Schmitt trigger produces a high output only when __________. |
The upper threshold level is exceeded. |
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Schmitt triggers are also called ___________. |
Squaring amplifiers |
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The purpose of a Schmitt trigger is to _____________. |
Convert any input to constant amplitude pulses. |
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A Schmitt trigger produces a high output only when __________. |
The upper threshold level is exceeded. |
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Schmitt triggers are also called ___________. |
Squaring amplifiers |
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The purpose of a Schmitt trigger is to _____________. |
Convert any input to constant amplitude pulses. |
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Schmitt triggers produce an output pulse anytime ....... |
The input exceeds the input threshold level. |
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The purpose of Amplitude Modulation is to ____________. |
Transmit intelligence over long distances. |
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The frequency range of AM receivers is ____________. |
535 KHz to 1605 KHz. |
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The purpose of AM receivers is to ___________. |
Receive radio waves. |
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If a signal measurement is incorrect between functional blocks, the fault is in _____________. |
The preceding functional blocks. |
