ANACOM 1/1 Module Setup Procedures

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of the CERAMIC BANDPASS FILTER block in the procedure?

  • To amplify the audio signal
  • To pass the upper sideband while blocking the lower sideband (correct)
  • To ensure the output signal has constant amplitude
  • To modulate the audio frequency signal

Which initial condition does NOT need to be satisfied before powering on the ANACOM 1/1 board?

  • AUDIO INPUT SELECT switch in INT position
  • OUTPUT AMPLIFIER’s GAIN preset in fully clockwise position
  • SPEAKER switch in ON position (correct)
  • MODE switch in SSB position

What happens to the waveform at t.p.20 after passing through the CERAMIC BANDPASS FILTER block?

  • It shows random fluctuations in amplitude
  • It changes to a square wave form
  • It becomes distorted by external noise
  • It appears as a good, clean sine wave (correct)

What adjustment can be made to vary the modulating frequency of the audio signal?

<p>Turn the AUDIO OSCILLATOR’s FREQUENCY preset (C)</p> Signup and view all the answers

What does the output signal at t.p.20 reveal about the performance of the CERAMIC BANDPASS FILTER?

<p>It confirms the filter is only passing the upper sideband (B)</p> Signup and view all the answers

What initial position should the BALANCE preset be set to before monitoring outputs?

<p>Fully clockwise position (A)</p> Signup and view all the answers

How does changing the modulating frequency affect the amplitude of the signal at the output of the CERAMIC BANDPASS FILTER?

<p>It results in variation of output signal amplitude (C)</p> Signup and view all the answers

What is the purpose of examining the waveforms in the BALANCE MODULATOR & BANDPASS FILTER CIRCUIT 1 block?

<p>To verify that output waveforms match expected patterns (D)</p> Signup and view all the answers

Which preset position should the AUDIO OSCILLATOR’s AMPLITUDE be in for proper conditions on the ANACOM 1/1 board?

<p>Fully clockwise position (B)</p> Signup and view all the answers

What is the required setting for the MODE switch on the ANACOM 1/1 board?

<p>SSB position (D)</p> Signup and view all the answers

What should the OUTPUT AMPLIFIER's GAIN preset be set to on the ANACOM 1/1 board?

<p>Fully counter-clockwise position (A)</p> Signup and view all the answers

When the AMPLITUDE preset is turned fully counter-clockwise, what happens to the monitored output signal from ANACOM 1/1?

<p>The amplitude drops to zero (A)</p> Signup and view all the answers

In order to monitor the I.F. AMPLIFIER 2 output on the ANACOM 1/2 module, what should you adjust?

<p>TUNING dial (D)</p> Signup and view all the answers

What must be ensured about the RX INPUT SELECT switch for proper operation?

<p>It should be in ANT position (C)</p> Signup and view all the answers

What effect does touching ANACOM 1/1’s antenna have on the SSB waveform at t.p. 13?

<p>It decreases the amplitude (B)</p> Signup and view all the answers

What is the correct position for the AGC switch on the ANACOM 1/1 board?

<p>IN position (B)</p> Signup and view all the answers

What is the result of adjusting the CARRIER FREQUENCY preset to 450 kHz?

<p>It allows modulation of the carrier with the audio signal. (B)</p> Signup and view all the answers

What should be monitored at t.p.52 when varying the frequency of the signal generator?

<p>The DC voltage corresponding to frequency changes. (D)</p> Signup and view all the answers

When applying the output from the Foster-Seeley block to the LOW PASS FILTER, what component should be removed?

<p>The high-frequency ripple component. (D)</p> Signup and view all the answers

How is the FM signal modulated in this experiment?

<p>By both the audio input and the noise input. (C)</p> Signup and view all the answers

What is the amplitude of the sinusoidal output used to test the Foster-Seeley detector?

<p>1V (p-p) for the initial input. (B)</p> Signup and view all the answers

What is observed at t.p.14 during the monitoring phase?

<p>The audio modulating signal. (B)</p> Signup and view all the answers

What effect does applying a 2 kHz noise signal have on the FM signal?

<p>It introduces additional amplitude modulation to the FM signal. (A)</p> Signup and view all the answers

What should the curve represent when plotting DC level against frequency after varying the signal generator's frequency?

<p>A curve that resembles the expected output pattern. (A)</p> Signup and view all the answers

What must be adjusted in MODULATOR 2 to achieve equal amplitude of frequency components in the DSK signal?

<p>GAIN control (B)</p> Signup and view all the answers

What frequency corresponds to a data bit value of ‘1’ in the FSK signal?

<p>1.44 MHz (B)</p> Signup and view all the answers

What effect does the higher incoming frequency have on the output voltage of MODICOM 5/2’s FSK DEMODULATOR?

<p>It increases the output voltage (D)</p> Signup and view all the answers

What is the main purpose of the low pass filtering stage in the demodulation process?

<p>To remove unwanted frequency components (B)</p> Signup and view all the answers

What adjustment is necessary for the output pulses of COMPARATOR 1 to match the pulse width of MODICOM 5/1’s NRZ(L) output?

<p>Set the BIAS level (D)</p> Signup and view all the answers

What should happen after turning on MODICOM 3/1’s SYNC CODE GENERATOR?

<p>Ensure synchronization of codes between A/D and D/A converters (D)</p> Signup and view all the answers

When using function generators with MODICOM 3/1, what does the user check at MODICOM 3/2’s analog outputs?

<p>The inputs are successfully reconstructed (B)</p> Signup and view all the answers

What is the end result of frequency modulation by MODICOM 5/1’s NRZ(L) output?

<p>A frequency-modulated carrier signal (C)</p> Signup and view all the answers

What is the effect of increasing the sampling frequency on the ability to reconstruct the original waveform?

<p>It allows for better reconstruction of the original waveform. (C)</p> Signup and view all the answers

How does varying the sampling duty cycle affect the output amplitude of the filter in a practical digital communications system?

<p>The output amplitude remains independent of the duty cycle. (C)</p> Signup and view all the answers

What is the primary purpose of the sample/hold circuit in a digital communications system?

<p>To hold each sampled signal before low-pass filtering. (B)</p> Signup and view all the answers

When comparing the outputs of the Second Order Low Pass Filter and Fourth Order Low Pass Filter, what factor is being analyzed?

<p>The amount of distortion in the waveforms. (A)</p> Signup and view all the answers

At what sampling frequency does the amplitude of the filter output become equal to that of the original analog input?

<p>When the sampling frequency is at least 32 kHz. (B)</p> Signup and view all the answers

What happens to the filter output signal as the sampling frequency is changed using the FREQUENCY SELECTOR switch?

<p>It alters the output waveform significantly. (A)</p> Signup and view all the answers

What is the significance of using a 50% duty cycle in the sampling process?

<p>It provides a balanced sampling and holding time. (B)</p> Signup and view all the answers

What is an expected outcome when displaying the SAMPLE/HOLD OUTPUT on an oscilloscope?

<p>The output will resemble the original sine wave. (D)</p> Signup and view all the answers

Flashcards are hidden until you start studying

Study Notes

ANACOM 1/1 Module Setup and Operation

  • Connect the ANACOM 1/1 module to the power supply properly.
  • Set the following initial board conditions:
    • AUDIO INPUT SELECT switch to INT
    • MODE switch to SSB
    • OUTPUT AMPLIFIER’s GAIN preset fully clockwise
    • SPEAKER switch in OFF position.
  • Power on the ANACOM 1/1 board.
  • Adjust the AUDIO OSCILLATOR block’s AMPLITUDE preset to maximum, and verify output sine wave frequency using an oscilloscope (300Hz to 3.4KHz).
  • Set the BALANCE preset in BALANCE MODULATOR & BANDPASS FILTER CIRCUIT 1 fully clockwise.
  • Monitor output from BALANCE MODULATOR & BANDPASS FILTER CIRCUIT 1 and 2 at specified test points.
  • Observe DSBSC output entering the CERAMIC BANDPASS FILTER, focusing on upper sideband transmission only.

Monitoring and Signal Examination

  • Verify the output of the CERAMIC BANDPASS FILTER using an oscilloscope; check for clean sine wave.
  • Note any amplitude variation in filter output due to frequency response changes.
  • Ensure all other initial conditions are met for further operations, including proper settings for TX OUTPUT SELECT and AUDIO AMPLIFIER’s VOLUME.
  • Check the Transmitter’s output signal (t.p. 13) for good SSB waveform consistency across AUDIO OSCILLATOR’s FREQUENCY preset adjustments.
  • Confirm zero amplitude output when the AMPLITUDE preset is fully counter-clockwise.

Transmitter-Receiver Communication

  • Test SSB signal transmission to ANACOM 1/2 Receiver and verify through antenna loading effects.
  • On receiver module, adjust settings to maximize I.F. AMPLIFIER 2 block output.

Frequency Modulation and Demodulation with Foster-Seeley Detector

  • Connect a signal generator (1V p-p, 400 kHz) to the Foster-Seeley Detector block.
  • Vary signal frequency from 430 kHz to 480 kHz, recording DC voltage at t.p.52 in 5 kHz steps for a frequency-voltage curve.
  • Adjust CARRIER FREQUENCY preset to 450 kHz, modulate the signal from AUDIO OSCILLATOR, and apply it to the Foster-Seeley block.
  • Monitor combined signals to identify sine wave and high-frequency ripple components.
  • Use LOW PASS FILTER/AMPLIFIER to remove ripple and observe the filtered output.

Noise Impact on System

  • Introduce noise (100 mV p-p, 2 kHz) to observe effects on FM output.
  • Monitor input audio and LOW PASS FILTER output to evaluate ripple presence.
  • Use SAMPLE/HOLD OUTPUT linked to FOURTH ORDER LOW PASS FILTER to analyze original waveform reconstruction.

Frequency and Duty Cycle Adjustments

  • Vary sampling frequency and duty cycle to examine filter output amplitude consistency.
  • Compare outputs from FIRST and SECOND ORDER LOW PASS FILTERS under varied sampling frequencies for distortion assessment.
  • Primary objective: Perform frequency modulation signal generation and detection using MATLAB Simulink.
  • Adjust GAIN control on MODULATOR 2 to balance frequency components of DSK signal.
  • Analyze the FSK signal and note variations during data changes (0 and 1).
  • Remove unwanted carrier frequencies using low pass filtering and ensure output signal squaring with the correct pulse width adjustment.

System Functionality Verification

  • Confirm synchronization across components and functionality of the FSK Transmitter-Receiver system.
  • Allow testing of analog inputs and real-time reconstruction at modular outputs.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team
Use Quizgecko on...
Browser
Browser