Agilent Technologies E8285A Manual page 132

Periodic Adjustments/Calibration
Periodic Calibration Menu Descriptions
Timebase Reference Using a Counter
This program is used to manually tune the timebase reference using a frequency
counter as the time standard. This procedure has two basic steps:
1. Coarse and fine manual adjustment of the two timebase tuning DACs.
2. Downloading the DAC settings into the Test Set.
If you have not already adjusted the two timebase tuning DACs, exit the program
if needed (by selecting the Adj user key), and follow the instructions in
the Timebase Latches" on page
If you have adjusted the timebase DACs, run this program and select the Cal user
key to make the setting permanent.
As an alternate method, you can select the option Timebase Reference
Using a Source (see following section) and adjust the timebase to a time
standard connect to the front-panel ANTENNA IN connector.
Timebase Reference Using a Source
This program automatically tunes the timebase tuning DACs to the signal at the
front-panel ANTENNA IN connector, which is input at the frequency that is keyed
in from the front-panel keypad. If an external 10 MHz reference is being used, it
must be disconnected.
In order for the calibration to be valid, the signal applied to the ANTENNA IN
connector must have the following characteristics.
1. The level should be between −30 and +20 dBm (0.001 and 100 mW).
2. The frequency should be between 800 and 1000 MHz.
3. The frequency must be as accurate as the application of the Test Set requires.
4. The Test Set must be able to tune to within 10 or 100 kHz of the reference
5. The signal must be a CW signal. Specifically, any FM must be less than 100 Hz
6. The coarse tune DAC must be between 3 and 250 (decimal); otherwise, the
After the coarse and fine tune DAC settings have been determined, the values are
downloaded into the Test Set's memory.
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S:\agilent\e8285\ALR\Book\chapters\period_adj.fm
signal with the Test Set's current timebase reference settings. If this condition is
not met, either the keyed-in frequency is incorrect or the Test Set is faulty.
peak as measured by the Test Set.
frequency of the source is out of reach by the tuning DAC.
135.
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