Performing The Ytf Self-Calibration Routine - HP 8590 E-Series User Manual

Performing the YTF Self-Calibration Routine

(HP 8592L, HP 85933, HP 85953, or HP 85963 Only)
For HP 8592L, HP 85933, HP 85953, and HP 85963 spectrum analyzers only, the YTF
self-calibration routine should be performed periodically. See "When Is Self-Calibration
Needed?" in the following section for some helpful guidelines on how often the self-calibration
routines should be performed.
1. For the HP 8592L, HP 85933, and HP 85963 connect a low-loss cable (such as HP part
number 8120-5148) from 100 MHz COMB OUT to the spectrum analyzer input. For the
HP 8595E connect the cable from the CAL OUT to the spectrum analyzer input.
2. Press LCAL), then CAL YTF . The YTF self-calibration routine completes in approximately:
3. Press a), then CAL STORE to save the calibration factors in memory.
4. Press (PRESET) to return to normal operation.
When Is Self-Calibration Needed?
While it is difficult to provide general advice for your specific measurement needs, the
following suggestions may help you decide when to use the self-calibration features:
1. Perform the frequency and amplitude self-calibration routines whenever the instrument
experiences significant environmental changes such as temperature (f5 "C), humidity, shock,
or vibration (such as may occur during shipping or transport). This is especially important
if the frequency and amplitude self-calibration routines were performed last in a different
environment.
2. If the environment is relatively stable (for example, a lab environment), use
CAL FREQ & AMPTD monthly. After being turned off overnight, the spectrum analyzer will
need to warm up, but should not require self-calibration.
3. To achieve optimal amplitude accuracy for relative measurements:
a. Keep the spectrum analyzer in a stable environment.
c. Keep the spectrum analyzer turned on between measurements.
normally smaller than the self-calibration uncertainty).
4. If you change the input signal for EXT REF IN, run the frequency and amplitude
self-calibration routines using CAL OUT. Amplitude calibration is required to improve IF
centering.
5. If preselector peaking (PRESEL PEAK ) has more than a 2 dB effect on the signal amplitude
when in BAND 1 or above, and in a single band sweep, then perform the YTF self-calibration
routine and store the data with CAL STORE . The YTF self-calibration routine improves the
preselector default values. (HP 8592L, HP 85933, HP 85956 or HP 859622 only.)
2-18 Getting Started
Model Number Calibration Time
HP 8592L 7 minutes
HP 85933 7 minutes
HP 85953 3 minutes
HP 85963 5 minutes