Service Adjustments - Wavetek 39A Maintenance Manual

When the correct password has been entered from the keyboard the display changes to the
opening screen of the calibration routine and calibration can proceed as described in the
Calibration Routine section. If an incorrect password is entered the message INCORRECT
PASSWORD! is shown for two seconds before the display reverts to the UTILITY menu.
With the opening screen of the calibration routine displayed after correctly entering the password,
the password can be changed by pressing password... soft−key and following the procedure
described in Setting the Password. If the password is set to 0000 again, password protection is
removed.
The password is held in EEPROM and will not be lost when the memory battery back−up is lost.
In the event of the password being forgotten, contact the manufacturer for help in resetting the
instrument.
Calibration Routine
The calibration procedure proper is entered by pressing continue on the opening Calibration
screen; pressing exit returns the display to the UTILITY menu. Pressing tests... calls a
menu of basic hardware checks used at production test which are self-explanatory. At each step
the display changes to prompt the user to adjust the rotary control or cursor keys, until the
reading on the specified instrument is at the value given. The cursor keys provide coarse
adjustment, and the rotary control fine adjustment. Pressing next increments the procedure to
the next step; pressing CE decrements back to the previous step. Alternatively, pressing exit
returns the display to the last CAL screen at which the user can choose to either save new
values, recall old values
The first two displays (CAL 00 and CAL 01) specify the connections and adjustment method. The
next display (CAL 02) allows the starting channel to be chosen in multi-channel instruments;
ignore CAL02 in this instrument and step on to CAL03. The subsequent displays, CAL 03 to
CAL 55, permit all adjustable parameters to be calibrated.
The full procedure is as follows:
CAL 03
CAL 04
CAL 05
CAL 06
CAL 07
CAL 08
CAL 09
CAL 10
CAL 11
CAL 12
CAL 13
CAL 14
CAL 15
CAL 55

Service Adjustments

The following 3 sections contain information about adjustments which are normally done once
only at the factory. These may need to be repeated if a component in the relevant area is
changed.
or calibrate again.
CH1. DC offset zero.
CH1. DC offset at + full scale.
CH1. DC offset at − full scale.
CH1. Multiplier zero.
CH1. Multiplier offset.
CH1. Waveform offset.
CH1. Output level at full−scale
CH1. 20dB attenuator
CH1. 40dB attenuator
CH1. 10dB attenuator
CH1. Not used.
CH1. Not used.
CH1. Not used.
Clock calibrate
Adjust for 0V ± 5mV.
Adjust for + 10V ± 10mV.
Check for –10V ± 3%
Adjust for minimum Volts AC
Adjust for 0V ± 5mV.
Adjust for 0V ± 5mV.
Adjust for 10V ± 10mV.
Adjust for 1V ± 1mV.
Adjust for 0.1V ± .1mV.
Adjust for 2.236V AC ± 10mV.
Adjust for 10.00000 MHz at SYNC OUT.
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