Tektronix 7D14, Instruction Manual

Page: 55 / 133

Calibration— 7D14
CHANNEL A CHECK
Equipment Required
1. Indicator Oscilloscope
7. GR 50-ohm in-line termination
2. Amplifier unit
8. GR to BNC male adapter
3. Time-base unit
9. 5-nanosecond GR cable
4. High-frequency constant-amplitude sine-wave generator
10. 42-inch BNC cable
5. Medium-frequency constant-amplitude sine-wave gen-
11. 18-inch BNC cable
erator
12. BNC T connector
6. Low-frequency constant-amplitude sine-wave generator 13. GR 10X attenuator
Control Settings
Set the controls as given under Preliminary Control
Settings.
NOTE
In steps one through four, the exact reading obtained
depends on the accuracy of the generator dial setting.
1. Check CH A INPUT Frequency Range
a. Connect the high-frequency constant-amplitude sine­
wave generator to the amplifier unit input through the five-
nanosecond GR cable, 10X GR attenuator, and 50-ohm
in-line termination, in given order.
b. Set the amplifier unit for a vertical deflection factor
of 50 millivolts/division.
c. Set the high-frequency generator for a two-division
(100 mV) display at the 3-MHz reference frequency.
d. Disconnect the 50-ohm in-line termination from the
amplifier unit input, and reconnect it to the CH A INPUT
connector.
e. Set the high-frequency generator for a 500-MHz out­
put.
f. CHECK—The readout display should show a steady
count of about 500.00000 MHz. Change the dial setting if
necessary to obtain a count of at least 500 MHz.
NOTE
This procedure checks the 7D14 frequency range to
500 MHz. To check the frequency range to the maxi­
mum limit as given under Performance Requirement
in Section 1, use a constant-amplitude generator with
at least a 525-MHz output.
g. Set the INPUT SENS switch to 50 Ω/100 mV.
h. Replace the 50-ohm in-line termination on the high-
frequency generator output with a GR to BNC male
adapter, and reconnect the generator to the CH A INPUT
connector.
i. CHECK— The readout display for the same count
obtained in part f of this step (at least 500 MHz).
j. Disconnect all test equipment.
2. Check CH A INPUT 50 Ω Sensitivity and Low-
Frequency Range (AC-COUPLING)
a. Change the following control settings:
7D14
INPUT SENS 50Ω/1V
MEASUREMENT INTERVAL 1s
b. Connect the low-frequency constant-amplitude gener­
ator to the amplifier unit input connector through the 42-
inch BNC cable and BNC T connector. Connect the output
5-5