Mhz Standard - Agilent Technologies 83620A Service Manual

All manuals and user guides at all-guides.com

1. 10 MHz Standard

Description and Procedure
his procedure adjusts the frequency accuracy of the internal 10 MHz time
base. his adjustment should be done on a regular basis if absolute frequency
accuracy is important (see Figure 3-3.)
For best accuracy, readjust the 10 MHz timebase oscillator after the synthesizer
has been on or in standby for 24 hours. See \Accuracy Versus Adjustment
Interval," following this adjustment, for information on how to determine a
periodic adjustment schedule.
After the timebase is adjusted, the timebase frequency should stay within the
aging rate if the following things happen:
he time base oven does not cool down.
he instrument keeps the same orientation with respect to the earth's
magnetic eld.
he instrument stays at the same altitude.
he instrument does not receive any mechanical shock.
If the time base oven cools (the instrument is disconnected from AC power),
you may have to readjust the time base frequency after a new warm-up cycle.
ypically, however, the time base frequency returns to within
original frequency.
You can adjust the internal timebase after reconnecting AC
Note
power for 10 minutes, but for best accuracy, test again after the
instrument has been on or in standby for 24 hours.
Frequency changes, due either to a change in orientation with respect to the
earth's magnetic eld or to a change in altitude, are usually eliminated when
the instrument is returned to its original position. A frequency change due to
mechanical shock usually appears as a xed frequency error.
HP 8360
6
1 Hz of the
Adjustments 3-5
10 MHz tandard