HP TM 11-6625-2779-14&P - Manual (Page 40)

Section V Model 3555B
Figure 5-6. Bridging Loss Test Set-Up
j. Change the bridge resistors in Figure 5-4 to
135 ohms +0.1% and change the 3555B
FUNCTION to 135 BAL. Check the return
loss between 1kHz and 600kHz. The
return loss must be better than 26dB down
from the reference.
k. Change the 3555B input connection to the
75 UNBAL jack. Change the resistors in
Figure 5-4 to 75 ohms +0.1% and change
the 3555B FUNCTION to CARRIER 75
UNBAL.
l. Check the return loss between 1kHz and
3MHz. The return loss must be better than
30dB down from the reference.
5-11. FILTER RESPONSE CHECKS.
a.
C MSG FILTER RESPONSE
1. Connect the equipment as shown in
Figure 5-5 with S1 in position 1 and
set the 3555B controls as follows:
FUNCTION......... VF/Nm 600
INPUT ............ NOISE BRDG
RANGE ....................... 0dBm
2. Adjust the output of the 654A for
0dBm at a frequency of 1 kHz.
3. Check the frequencies listed in Table
5-5 for the tolerances indicated.
b. 3kHz FLAT FILTER RESPONSE
1.
Set the 654A frequency to 1kHz and
adjust the output level for 0dBm.
2. Check the frequencies listed in Table
5-5 for the tolerances indicated.
c. 15kHz FLAT FILTER RESPONSE
Table 5-5. Filter Response Checks
FREQUENCY C MSG (dBm) 3kHz FLAT (dBm) 15kHz FLAT (dBm) PROGRAM (dBm)
60Hz -55.7 ±2 0
±
1.75 0
±
1.75
200Hz -25
±
2 -17.3
±
2
250Hz 0
±
1 0 ±1
500Hz -7.5
±
1 -6.6
±
1
1kHz 0(Ref) 0(Ref) 0(Ref) 0(Ref)
2kHz -1.3
±
1 -0.5
±
1.75 4.8
±
2
2.5kHz -1.4
±
1 -1.5
±
2
3kHz -3
±
3 +6.5
±
2
4kHz -14.5 ±3 +6.5
±
2
5kHz -28.5
±
3 0
±
1 +6.5
±
2
6kHz +6.4
±
3
8kHz +4 ±3
10kHz -0.5
±
1.75 -8.5
±
4
12.5kHz -1.5 ±2
15kHz -3 ±3
5-6