Tektronix 1L10, Instruction Manual

Page: 22 / 72

Maintenance and Calibration— Type 1 LI 0
Fig. 4 -8 . Equipment setup for resolution check.
Resolution Check
1. Connect up the equipment as shown in Fig. 4-8.
2. Set the front-panel controls as follows:
RF CENTER FREQ
10
VERTICAL POSITION
Midrange
R-F ATTEN All OFF
VERTICAL DISPLAY
LIN
GAIN
Midrange
DISPERSION-KC/CM 2
COUPLED RESOLUTION
2
INT OSC EXT OSC
INT OSC
Oscilloscope Sweep Rate 20 mSEC
3. On the Harmonic M odulator Unit, set the MOD 2
switch to O N and the 60 me TRAP switch to IN.
4. Set the Type 180A Time-Mark Generator for an output
frequency of 5 me.
5. Using the RF CENTER FREQ control of the Type 1 LI 0,
tune the 2nd harmonic (10 me) of the Type 180A signal to
the center of the screen.
6. Set the audio generator for an output frequency of
1 kc and adjust the controls on the Harmonic Modulator
Unit so that at least two modulation markers (one on each
side of center frequency) are visible.
7. Set the DISPERSION-KC/CM and COUPLED RESOLU­
TIO N switches to .2 and center the display on the screen
with the FINE RF CENTER FREQ control.
8. W ith the VERTICAL POSITION control, position the
bottom o f the display to the bottom line on the graticule.
9. Set the GAIN control so that the center frequency
marker is six centimeters in amplitude.
Fig. 4 -9 . Display of a 1-kc modulated signal with the COUPLED
RESOLUTION control set at 2 -K C /C M and the DISPERSION-KC/CM
at .5. Notice that the valleys in the display do not come to the
baseline.
4 - 6