Rohde & Schwarz ZVB 14, Service Manual

Page: 150 / 198

Instrument Construction and Function Description R&S ZVB
1145.1078.82 3.82 E-4
Testing the LO Divider Board
It is assumed that the LO-synthesizer section (synthesizer2 for 3-port and 4-port-models, synthesizer 1
for 2-port-models) is OK.
Disconnect cable W656, WW659, W666 or W669, depending on which LO-branch is being tested.
Connect the output under test (X6, X7, X8 or X9) to the spectrum analyzer using the adapter cable.
Enter service- function 2.21.2.18.17512345 (IF = 17.512345 MHz).
Set the R&S ZVB to the CW sweep mode.
Set the frequencies listed in the table.
Frequency R&S ZVB Frequency spec.
= Frq R&S ZVB + IF
Level
300 kHz (R&S ZVB4/8
only)
17.812345 MHz 5 dBm to 14 dBm
10 MHz 27.512345 MHz 5 dBm to 14 dBm
50 MHz 67.512345 MHz 5 dBm to 14 dBm
1 GHz 1.017512345 GHz 5 dBm to 14 dBm
3 GHz 3.017512345 GHz 5 dBm to 14 dBm
6 GHz 6.017512345 GHz 5 dBm to 19 dBm
8 GHz 8.017512345 GHz 5 dBm to 19 dBm
With the stated levels, the cable loss must still be taken into account. For the specified cable, it is
0.25 dB/GHz (0.5 m) or 0.5 dB/GHz (1 m).
If the measured values are below the levels in the table, the board must be replaced.