Giga-tronics GT 9000, Operation & Maintenance Manual

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4.1.9 AM Calibration
After verifying the AM/FM generators, use these steps to calibrate the AM output. Parts of the
equipment setup can also be used in the FM calibration steps.
Equipment Setup
1. On the front panel connect an external function generator with a BNC tee connector to
AM IN. Connect a scope at Channel 1 to the BNC tee. Ensure that the scope displays a
clean sine wave.
2. Use the external generator to apply a 2 Vpp, 1 kHz sine wave to AM IN. Measure the
sine wave on the scope to ensure accuracy.
3. Connect the mixer/divider to RF OUT on the front panel. Also connect the LO signal
generator to the mixer. The LO generator is set for 4.2 GHz at +10 dBm.
4. Connect the mixer IF OUT to the 8902A measuring receiver with filters set at 50 Hz
and 15 kHz.
5. Select the AM mode with p-p divide by 2 on the 8902A receiver. Optional: connect the
receiver modulation output to channel 2 on the scope.
6. Select 4 GHz and 0 dBm on the UUT.
AM External Procedures
1. Select AM EXT at 50%.
2. On A10, if required, adjust R5 for a 50% reading on the receiver.
AM Internal Procedures (Option 24 only)
1. Select AM INT SIN at 50% and at a 1 kHz rate.
2. On A6-A1, if required, adjust R4 for a reading of 50% +0.05%.
3. Select AM INT TRI. Verify that the receiver reads 50% +0.5%.
4. Select AM INT SQR at 50%.
5. On the receiver, turn off the 50 Hz and 15 kHz filters.
6. On A6-A1, if required, adjust R9 for a receiver reading of 50% +0.05%.
Model GT 9000 Microwave Synthesizer
4-8
Manual No. 120AM00250, Rev C, September 1998