Tektronix 491, Maintenance Manual

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SECTION 5
PERFORMANCE CHECK
This section of the manual provides a means of checking
the performance of the Type 491. It is intended to check
the calibration of the instrument without performing the com-
plete Calibration Procedure. The Performance Check does
not include the adjustment of any internal controls. Failure
to meet the requirements given in this procedure indicates the
need for internal checks or adjustments, details of which will
be found in the Calibration Procedure.
Recommended Equipment
The following equipment is recommended for a complete
performance check. Specifications given are the minimum
necessary to perform this procedure. All equipment must
be calibrated and operating within the original specifications.
If equipment is substituted, it must meet or exceed the speci-
fications of the recommended equipment.
For accuracy and convenience, special calibration fixtures
may be used in this procedure. These fixtures are available
from Tektronix, Inc. Order by part number through your
local Tektronix Field Office or representative.
1. Test Oscilloscope: Minimum deflection factor, .01 volts/
division. Frequency response DC to 10 MHz. Any Tektronix
oscilloscope and plug-in unit with the above requirements and
a
1×
and a
10×
probe such as P6010
(10×)
and P6011
( 1 × ) .
2. Time-Mark Generator. Marker outputs, .5s to .1 µs
and frequency outputs of 20 MHz, 50 MHz, 100 MHz and
200 MHz; accuracy 0.001%. Tektronix Type 184 Time-Mark
Generator,
3. Audio Signal Generator: Frequency range 10 Hz to
1 MHz, variable output amplitude at least 10 volts peak to
peak, accuracy ±3%.
General Radio Model 1310A or
Hewlett-Packard Model 241A.
4. VHF Signal Generator: Frequency range 10 MHz to 400
MHz, accuracy ±1%, calibrated variable output 0 to –120
dBm. Hewlett-Packard Model 608D.
5. Constant Amplitude Signal Generator: 1 MHz to 10
MHz, output amplitude 1 V to 5 V peak to peak. Tektronix
Type 191 Constant Amplitude Signal Generator.
6. Step Attenuators: 1 dB and 10 dB steps, accuracy ±1.5
dB to 90 dB (below 1 GHz). Hewlett-Packard Type 355C and
355D Step Attenuators.
7. Harmonic Generator: Tektronix Calibration Fixture
067-0594-00.
8. 200 MHz Trap: Tektronix Calibration Fixture 067-0595-00.
9. Two (2) GR to BNC male adapters: Tektronix Part No.
017-0064-00.
10. Clip lead adapter,
BNC. Tektronix Part No. 013-
0076-00.
11. Termination, 50
Ω,
BNC. Tektronix Part No. 017-0049-
01.
12. BNC T connector. Tektronix Part No. 103-0030-00.
13. Two (2) BNC coaxial cables, 50 W. Tektronix Part
No. 012-0057-00.
14. 10 dB attenuator pad,
1
Type N fitting. Tektronix Part
No. 011-0085-00.
15. 20 dB attenuator pad,
1
Type N fittings. Tektronix Part
No. 011-0086-00.
16. 40 dB attenuator pad, 1 Type N fittings. Tektronix Part
No. 011-0087-00.
17. Two (2) adapters, BNC male of N female.
1
Tektronix
Part No. 103-0058-00,
18. Two (2) adapters, BNC female to N male. 1 Tektronix
Part No. 103-0045-00.
The following additional equipment is required to check
the instrument sensitivity, flatness and dial calibration.
Group II (optional)
Swept-Frequency Generator, with a frequency range 130
MHz to 280 MHz and an amplitude variation which is less
than 0.25 dB, Suggested equipment-Kay Type 121 C Multi-
Sweep Generator.
Group III
RF Signal Generatars with calibrated frequency and out-
put power: Frequency range 10 MHz to 40 GHz, accuracy
±1%; output power -100 dBm to -30 dBm, accuracy ± 1
dB/dB; output impedance 50
Ω.
Suggested equipment:
Hewlett-Packard 612A UHF Signal Generator, 450 MHz
to 1230 MHz.
Hewlett-Packard 8614A UHF Signal Generator, 800 MHz
to 2400 MHz.
Hewlett-Packard 8616A UHF Signal Generator, 1800 MHz
to 4500 MHz.
Polarad 1107 Microwave Signal Generator, 3.8 GHz to
8.2 GHz.
Polarad 1108 Microwave Signal Generator, 6.95 GHz to
11.0 GHz.
Hewlett-Packard 626A SH F Signal Generator, 10.0 GHz
to 15.5 GHz.
Hewlett-Packard 628A SHF Signal Generator, 15.0 GHz
to 21.0 GHz.
Hewlett-Packard 938 Frequency Doubler set, 18.0 GHz to
26.5 GHz.
Hewlett-Packard 940 Frequency Doubler set, 26.5 GHz to
40.0 GHz.
Hewlett-Packard X281 Wave-guide to coaxial adapter.
Hewlett-Packard NP292A Wave-guide to coaxial adapter.
1 Supplied with accessories kit.
5-1