Device Response In The Time Domain - HP 8753E User Manual

7. To enter the relative velocity of the cable under test, press:
and enter a velocity factor for your cable under test.
Most cables have a relative velocity of 0.66 (for polyethylene dielectrics) or 0.7
Note
(for teflon dielectrics). If you would like the markers to read actual one-way
distance rather than return trip distance, enter one-half the actual velocity
factor. Then the markers will read the actual round trip distance to the
reflection of interest rather than the "electrical length" that assumes a relative
velocity of 1.
where cr is the relative permittivity of the cable dielectric
8. lb position the marker on the reflection of interest, press:
In this example, the velocity factor was set to one-half the actual value, so the marker reads
the time and distance to the reflection.
9. To position a marker at each reflection of interest, as shown in Figure 2-65, press:
front panel keypad after each key press.
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Figure 2-65. Device Response in the Time Domain
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