Tektronix 1A5 Instruction Manual page 71

Type 1A5 Controls
P O S ITIO N
A Input AC-GND-DC
B Input AC-GND-DC
VOLT S/ CM
VARIABLE
DISPLAY
STEP ATTEN BAL
Type 544 Oscilloscope Contro
Triggering L e vel
Triggering Mode
Triggering Source
Time/cm
Variable
Horizontal Display
S q u a re Wave Generator
R ep e t ition R a te Range
Multiplier
Hi Amplitude/Fast R i s e
+ Output
8. Noise
a. Equipment setup is shown in F
forms appear in Fig. 6-12.
F i g. 6-11. E q uipment se t up for s
Mi d r a n ge
DC
GND
1 mV
CAL
A-B
Midrange
l s
Fully Clockwise
Auto S ta bility
Norm
10 μs
Cal
Norm ( x1 )
1 kHz
CCW
Fas t Ri s e
i g . 6- 11 . Typical wa v e ­
t eps 8 through 12.
b- Connect the following components to the A INPUT
connector in the s e quence given:
GR-to-BNC 50 fl Termination (item 13)
GR 5 ns Cable (item 9)
2 — 10:1 - — 50 Ω — GR Type Attenuators (item 16)
1 — 5:1 — 50 Ω — GR Type Attenuator (item 15)
Type 106 S q uare Wave Generator + Output (item 3)
c. S e t the Oscilloscope Time/cm control to 10 μs and the
Triggering L e vel control to its clockwise limit. Set Intensity,
Focus and Astigmatism for optimum CRT viewing.
d. S et the Type 1A5 A Input AC
and the VOLT S/ CM control to 1 mV. Check that the UNCAL
lamp is off.
e. Set the Square Wave Generator Hi Amplitude-Fast Rise
switch to Fast Ris e , the R e petition Rate Range to 1 kHz, and
the Multiplier CCW. Increase the Square Wave Generator
+ Transition Amplitude to provide 2 s
CRT. (Caused by the upper and lower excursions of the
s q u a re wave being presented on a free running sweep.).
f. Decrease the + Transition Amplitude as neces
just eliminate the dark line between the two traces. Use Fig.
6-12 (A), (B) and (C) as guides. (The desired presentation is
obtained when a point is reached where doubt exists as to
whether the black line is or is not eliminated.) The two trace
centers are now s ep a rated by twice the RMS value of noise.
Calibration — Type 1A5
- GND-DC switch to DC
e p a rate traces on the
sa ry to
6-11