<p>ECE 351 ELECTROMAGNETICS</p><p>EXPERIMENT EM1</p><p>CROSSTALK IN WIRES</p><p>OBJECTIVE: The purpose of this experiment is to demonstrate the phenomena of crosstalk in wires and the effect that various wiring schemes have on crosstalk.</p><p>EQUIPMENT: Oscilloscope Krohn-Hite Function Generator (Model 2400) Connectors and Clip Leads Four Cable Assemblies</p><p>I. EQUIPMENT SETUP A. INITIAL SETTING ON OSCILLOSCOPE Select a Dual Trace CH 1 : Amplitude setting at 1 V/div. Ensure AC is selected. CH 2 : Amplitude setting at 10 mV/div. Ensure AC is selected.</p><p>A TRIGGER: COUPLING: AC SOURCE: CH 1 To lock onto the signal, adjust SLOPE and/or LEVEL.</p><p>B. FUNCTION GENERATOR MULTIPLIER (Hz) 10 K WAVEFORM Sinusoid D.C. OFFSET Off (by pushing knob in) AMPLITUDE Minimum FREQUENCY Minimum MODE (on right side) CONT</p><p>II. PROCEDURE A. CROSSTALK IN CABLE ASSEMBLY 1 (Non-twisted, separate ground).</p><p>1. Connect the test leads to cable assembly 1 as shown in figure a.</p><p>2. Adjust the Function Generator FREQUENCY to 30 kHz and the output level at V1 to 4.0 V p-p. Measure V2 (p-p).</p><p>1 3. Keeping V1 at 4.0 V p-p, measure V2 at 100 kHz.</p><p>4. Repeat this measurement (maintaining V1) at frequencies of 300, 500, 700 and 900 kHz. Continue for 1 and 3 MHz.</p><p>5. Switch the function generator to supply a triangle wave of frequency 100 kHz with V1 set to 4.0 V p-p. Sketch V1 and V2. Try to give an explanation for the shape of V2.</p><p>B. CROSSTALK IN CABLE ASSEMBLY 2 (Non-twisted, shared ground).</p><p>Connect the test leads to cable assembly 2 as shown in figure b. Switch the function generation back to a sinuosidal wave. Repeat steps 2,3 and 4 of part A.</p><p>C. CROSSTALK IN CABLE ASSEMBLY 3 (Twisted, separate ground).</p><p>Repeat part (B) for the twisted pair using the assembly shown in figure a. </p><p>D. CROSSTALK IN CABLE ASSEMBLY 4 (RG-58 coaxial cable).</p><p>Repeat again for the coaxial cable arrangement using the assembly shown in figure c. </p><p>III. ASSIGNMENT A. Your group should state the objective of this lab and write up your results </p><p>B. Provide a table which shows V2/V1 and 20*log(V2/V1) versus frequency for the results obtained in parts II. </p><p>C. Plot V2/V1 versus frequency using a semilog scale for frequency for all cases (i.e., put all cases on the same plot). Repeat this, but now plot 20*log(V2/V1) versus frequency using a semilog scale for frequency.</p><p>D. Comment on the differences observed in the various cases, giving possible explanations for the differences.</p><p>2 3</p>