Frequency (internal timebase) adjustment
The instrument stores a calibration constant that sets the crystal oscillator to put out exactly 10 MHz. The
instrument should have been running continuously for one hour prior to this calibration adjustment to ensure
timebase stability.
1. Set the frequency counter resolution to better than 0.01 ppm and the input termination to 50 Ω (if your fre-
quency counter does not have a 50 Ω input termination, you must provide an external termination).
2. Use the frequency counter to measure the output frequency for each setup in the following table.
Setup
Frequency
Amplitude
SCPI command
2
< 10 MHz
~ 1 Vpp
Output frequency is slightly less than 10 MHz
CAL:SET 2
3
> 10 MHz
Output frequency is slightly more than 10 MHz
CAL:SET 3
4
~ 10 MHz
Output frequency should be near 10 MHz
CAL:SET 4
5
[a]
10 MHz
Output frequency should be 10 MHz ± 1 ppm
CAL:SET 5
[a] Constants are stored after completing this setup.
3. Enter the measured frequency by using SCPI command.
4. To proceed:
a. If CAL? check return (+1), exit the calibration menu and perform
Internal Timebase Verification
b. If you are making all of the adjustments and then verifying the instrument’s performance, continue with the
next procedure in this section.
32
Keysight EDU33210 Series Service Guide
