Rohde & Schwarz ZVB 14, Service Manual

Page: 142 / 198

Instrument Construction and Function Description R&S ZVB
1145.1078.82 3.74 E-4
Testing the Reflectometer RM8
Generator levels
It is assumed that the synthesizer section (synthesizer1) associated with the reflectometer to be tested
is OK.
Loosen cable W514 (GEN -> Bridge unit) at both ends and screw off at the generator output GEN.
Note: When loosening, support the cable with a 7 mm spanner
Connect the generator output to the spectrum analyzer using the SMA cables () and adapter
SMA-N.
Set the power to 8 dBm
Set the R&S ZVB to the CW sweep mode.
Set the frequencies listed in the table.
Frequency Level 2nd harmonic 3rd harmonic
300 kHz 16 dBm --- ---
50 MHz 16 dBm < - 21 dBc < - 21 dBc
1 GHz 16 dBm < - 21 dBc < - 21 dBc
3 GHz 16 dBm < - 21 dBc < - 21 dBc
6 GHz 16 dBm < - 21 dBc ---
8 GHz 16 dBm < - 21 dBc ---
With the stated levels, the cable loss must still be taken into account. For the specified cable it is
0.25 dB/GHz.
Receiver levels
The following is assumed:
•
The LO synthesizer section (synthesizer1 mod. 04, synthesizer2) associated with the reflectometer
to be tested is OK.
•
The network controller associated with the reflectometer to be tested is OK.
•
One reflectometer in the instrument is functioning.
Loosen cable W515 (Bridge unit -> MEAS) and cable W518 (Bridge unit ^ REF) at both ends and
screw off at the MEAS and REF receiver inputs.
N.B.: When loosening, support the cable with a 7 mm spanner
Connect the receiver input (MEAS or REF) to a functioning instrument port using an adapter cable
and adapter SMA-N.
Set the R&S ZVB to the CW sweep mode.
Set the frequencies and output levels for the port used for the measurement as indicated in the
table and read off the level for the receiver to be tested (wave quantity ax or bx).