Section III Model 1415A
Figure 3-5
n.cr
I
WOR,z\@)OS REFL. COEFFICIENT 8
</ PICM-IOIL SYSTEM 0 SWEEP
,YE"T,C.L UlrYlriCll ".NUL .. . . . . SCAN . .
111
(11, .os IOI RESET MANUAL YORYbL I
VERT .01
POSITION DETllL
STEP SIGNAL
IN OUT *
//4& 'ECORDF OUT
/ -/
1415A-A-42A
b6
Connect STEP OUTPUT to SIGNAL IN. b. Multiply the result by the DISTANCE set-
ting which corresponds to the type of dielectric
Connect external system to SIGNAL OUT.
in the transmission line. For example:
To Locate a Discontinuity: 0.25 cm X 200 = 50 cm. (MAGNIFIER setting
does not enter into the calculation. ) The dis-
Adjust DISTANCE/TIME controls for a con-
continuity in this example is 50 cm from the
venient display of both incident step and reflec-
sampler (SIGNAL IN/OUT connectors ).
tion to be identified.
Note
Note
Refer to Paragraph 3-12 for RFIelimination
The above technique can be used to
procedure.
determine separation between any
Set MAGNIFIER DELAY to position the doton two points on the display.
the step rise, and note the dial reading. (For
maximum accuracy, switch to DETAIL and Measurement of Reflection Coefficient:
increase magnification, both horizontally and
vertically if necessary; measure from the 10%
@ Set VERNIER to CAL.
point on the step rise. )
Set MAGNIFIER DELAY to position the dot at @ Adjust REFL COEFFICIENT and VERT POSI-
the start of the reflection, and note the dial TION for a convenient, accurate reading of
reading. (Again, maximum accuracy can be the reflection amplitude in centimeters on the
obtained by using magnification and detailed CRT screen. DETAIL scanning may improve
scanning. ) accuracy of the indication.
a. Subtract the reading obtained in Step 4 9 Multiply amplitude reading in centimeters by
from that in Step 5. For example: 2.75 cm- the REFL COEFFICIENT setting to obtain the
2.50 cm = 0.25 cm. reflection coefficient of the discontinuity.
Figure 3- 5. Reflection Measurements
3- 6 01944-3 |
ACEC
