Stanford Research Systems SR844 User Manual page 152

5-8 Performance Tests
Wide Reserve Down
Select LOW NOISE Wide Reserve.
Close Resrv once
Select LOW NOISE Close Reserve.
Sensitivity Down once
Select 300 mV sensitivity.
3) Amplitude response is checked at various frequencies. For each frequency in the table below,
perform steps 3.1 through 3.2.
Test Frequencies
100 kHz
300 kHz
1 MHz
3 MHz
10 MHz
30 MHz
100 MHz
200 MHz
3.1) Set the RF synthesizer to the frequency in the table.
3.2) Wait for the SR844 UNLOCK indicator to turn off.
3.3) Wait for the CH1 reading to stabilize. Record the CH1 reading (dBm).
4) Add one 20 dB attenuator at the SIGNAL IN. The total attenuation at the SIGNAL IN is now
-23 dB. Press the following key sequence:
Sensitivity Down twice
Select 30 mV sensitivity.
5) Repeat step 3 at this sensitivity.
6) Add another 20 dB attenuator at the SIGNAL IN. The total attenuation at the SIGNAL IN is now -
43 dB. Press the following key sequence:
Sensitivity Down twice
Select 3 mV sensitivity.
7) Repeat step 3 at this sensitivity.
8) This completes the amplitude response test. Enter the results of this test into the test record at the
end of this chapter.
SR844 RF Lock-In Amplifier