Tektronix 492 Operator's Handbook

CALIBRATE CENTER FREQUENCY
READOUT
a . Change the Vertical Display to 10 dB / DIV . If the
instrument has phase lock , ensure that the PHASE LOCK
is de - activated or the FREQ SPAN / DIV is above 50 kHz
(
recommend setting of 10
MHz ) .
b . Tune the FREQUENCY to place the 100 MHz
calibrator signal over the center - span dot marker . Reduce
FREQ SPAN / DIV to 1 MHz , press the DEGAUSS button ,
and
fine tune
center
frequency
.
NOTE
Degauss function is inoperative when the FREQ
SPAN / DIV is less than 1 MHz .
c . Press the CAL button to activate the calibration
function ( button illuminated ) ; then adjust the FRE
QUENCY tuning control for a readout of 100 MHz . Press
the CAL button to deactivate the CAL mode and increase
FREQ SPAN / DIV to 20 MHz .
2-16
d . Check - center frequency accuracy at other mul
tiples of the 100 MHz calibrator signal . Approach each
check point from the low frequency side and degauss the
tuning coils of the oscillator as each check point is
approached .
Readout
should be within
± ( 5 MHz
+ 20 %
span / div ) or ( 0.2 % of center frequency + 20 % of
span / div )
whichever
is
greater
.
e . Return the frequency to 100 MHz .
CALIBRATE REFERENCE LEVEL
AND DYNAMIC RANGE
a . With the 100 MHz calibrator signal tuned to center
screen and the REF LEVEL at -20 dBm , set the FREQ
SPAN / DIV to 20 kHz , as indicated by the crt readout .
b . Alternately switch Vertical Display from 10 dB / DIV
to 2 dB / DIV
and adjust
AMPL
CAL
so the peak
amplitude
of the signal is the same for each logarithmic display
mode .
492
Operator's
Handbook

Tektronix 492 Specifications

General

Brand	Tektronix
Model	492
Category	Measuring Instruments
Language	English