Mhz Reference Adjustment-Ocxo (Non-Option 103) - HP 8562E Service Manual

11. 10 MHz Reference Adjustment-OCXO (Non-Option 103)

A21 OCXO assembly
Replacement oscillators are factory adjusted after a complete warmup and
after the specified aging rate has been achieved. Thus, readjustment should
typically not be necessary after oscillator replacement and is generally not
recommended.
10 MHz Reference Accuracy
The frequency of the internal 10 MHz frequency reference is compared to a known frequency
standard and adjusted for minimum frequency error. This procedure does not adjust the
short-term stability or long-term stability of the A21 10 MHz ovenized crystal oscillator
(OCXO). Stability is determined by the characteristics of the particular oscillator and the
environmental and warmup conditions to which it has been recently exposed. The spectrum
analyzer must be on continuously for at least 24 hours immediately prior to oscillator
adjustment to allow both the temperature and frequency of the oscillator to stabilize.
2-48 Adjustment Procedures