7) Make sure the on/off RF button works,
=> OK
8) Make sure the power output doesn't oscillate,
Connect the RF output to an oscilloscope (50Ohm)
=> RF output: there is no obvious oscillation
Connect the TP1 connector to an oscilloscope
=> check the oscillation with an oscilloscope and SR785 => OK
Connect the CTRL connector to an oscilloscope
=> check the oscillation with an oscilloscope and SR785 => OK
9) EXC check
Connect a function generator to the exc port.
Set the FG output to 1kHz 2Vpk. Check the signal TP1
Turn off the exc switch -> no output
Turn on the exc switch -> nominally 200mVpk
=> OK
10) Openloop transfer function
Connect SR785 FG->EXC TP2->CHA TP1->CHB
EXC 300mV 100Hz-100kHz 200 line
Network Analyzer (AG4395A)
EXC 0dBm TP1->CHA TP2->CHB, measure A/B
801 line
CHA: 0dBatt CHB: 0dBatt
1kHz~2MHz
UGF 133kHz, phase -133.19deg = PM 47deg
11) Calibrate the output with the trimmer on the front panel
13dB setting -> 12.89dBm (maximum setting)
12) Check MON, BIAS and CTRL outputs,
CTRL: 2.95V
MON(L): 6.5mV
BIAS(L): 1.81V
MON(R): 10.7mV
BIAS(R): 1.85V
13) Output check
4+0dB 3.99dBm
6 5.89
8 7.87
10 9.87
12 11.88
14 13.89
16 15.89
18 17.92
20 19.94
22 21.95
24 24.00
26 26.06
4dB+
0.0 3.99
0.2 4.17
0.4 4.36
0.6 4.56
0.8 4.75
1.0 4.94
1.2 5.13
1.4 5.32
1.6 5.53
1.8 5.73
2.0 5.92
2.2 6.10
16dB+
0.0 15.82
0.2 16.11
0.4 16.31
0.6 16.51
0.8 16.72
1.0 16.92
1.2 17.12
1.4 17.32
1.6 17.53
1.8 17.72
2.0 17.92
2.2 18.13
26dB+
0.0 26.06
0.2 26.27
0.4 26.46
0.6 26.58
0.8 26.68
1.0 26.69
1.2 26.70
1.4 3.98
1.6 3.99
1.8 3.99
2.0 3.99
2.2 3.99
|