Quantum Data 802BT, User Manual

Page: 58 / 744

48 Chapter 3 Administrative Tasks
CALF ?
The generator presents the following in response:
1089, 2589, 1993, 3223, 1148, 2633, 2059, 3279, 1000, 2505, 1990,
3219, 793, 787, 3382, 3509
Calibrating frequency
All frequencies associated with the generator are derived from a common frequency
reference, which can be calibrated using the rate calibration command RATC .
To reduce all frequency errors to zero:
1. Measure any convenient frequency from the generator using a very accurate frequency
counter.
For example, measure the horizontal TTL separate sync frequency with the DMT0660
format loaded and the horizontal rate temporarily set to 100KHz. Enter the following:
FMTL DMT0660; HRAT 100E3; ALLU
2. Measure the TTL horizontal sync frequency with the frequency counter.
3. Divide the frequency that you expect by the frequency that you measure on the
frequency counter and enter that ratio using the
RATC
command.
For example, if you measure 99.9955782499875 kHz, when you expect
100.000000000KHz, then divide 100.000000000KHz by 99.9950002499875kHz and
enter the following on the command line:
RATC 1.0000442194553987
This will raise all frequencies output by the generator and make them exact.