Anritsu MS2665C - Page 76

Section 3 MS2667C
3-20
(3) YTF offset voltage adjustment 1
1) Set the spectrum analyzer.
Center frequency : 4 GHz
Span : 400 MHz
2) On the spectrum analyzer, press “single” key.
3) After sweep of the spectrum analyzer is finished, check the X3 voltage (multimeter indicated). This voltage value
is V1.
4) Set the spectrum analyzer’s span to 401 MHz.
5) On the spectrum analyzer, press “single” key.
6) After sweep of the spectrum analyzer is finished, check the X3 voltage (multimeter indicated). This voltage value
is V2.
7) Adjust R287 on the LOCAL-SP2 (refer to Fig. 3-2-4) until the difference voltage between V1 and V2 is below ±1
mV, to repeat the procedure 1) to 6).
(4) YTF offset voltage adjustment 2
1) Set the spectrum analyzer.
Center frequency : 4 GHz
Span : 4 GHz
2) On the spectrum analyzer, press “single” key.
3) After sweep of the spectrum analyzer is finished, check the X21 voltage (multimeter indicated). This voltage
value is V1.
4) Set the spectrum analyzer’s span to 4.01 GHz.
5) On the spectrum analyzer, press “single” key.
6) After sweep of the spectrum analyzer is finished, check the X21 voltage (multimeter indicated). This voltage
value is V2.
7) Adjust R280 on the LOCAL-SP2 (refer to Fig. 3-2-4) until the difference voltage between V1 and V2 is below ±1
mV, to repeat the procedure 1) to 6).