This section of the manual provides a means of checking
12. BNC T connector. Tektronix Part No. 103-0030-00.
the performance of the Type 491. It is intended to check
13. Two (2) BNC coaxial cables, 50 W. Tektronix Part
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
14. 10 dB attenuator pad,1 Type N fitting. Tektronix Part
to meet the requirements given in this procedure indicates the
need for internal checks or adjustments, details of which will
15. 20 dB attenuator pad,1 Type N fittings. Tektronix Part
be found in the Calibration Procedure.
16. 40 dB attenuator pad,1 Type N fittings. Tektronix Part
The following equipment is recommended for a complete
17. Two (2) adapters, BNC male of N female.1 Tektronix
performance check. Specifications given are the minimum
necessary to perform this procedure. All equipment must
Part No. 103-0058-00,
be calibrated and operating within the original specifications.
18. Two (2) adapters, BNC female to N male.1 Tektronix
If equipment is substituted, it must meet or exceed the speci-
Part No. 103-0045-00.
fications of the recommended equipment.
The following additional equipment is required to check
For accuracy and convenience, special calibration fixtures
the instrument sensitivity, flatness and dial calibration.
may be used in this procedure. These fixtures are available
from Tektronix, Inc. Order by part number through your
Group II (optional)
local Tektronix Field Office or representative.
Swept-Frequency Generator, with a frequency range 130
MHz to 280 MHz and an amplitude variation which is less
division. Frequency response DC to 10 MHz. Any Tektronix
than 0.25 dB, Suggested equipment-Kay Type 121 C Multi-
oscilloscope and plug-in unit with the above requirements and
a 1 and a 10 probe such as P6010 (10) and P6011
RF Signal Generatars with calibrated frequency and out-
2. Time-Mark Generator. Marker outputs, .5s to .1 s
put power: Frequency range 10 MHz to 40 GHz, accuracy
and frequency outputs of 20 MHz, 50 MHz, 100 MHz and
1%; output power -100 dBm to -30 dBm, accuracy 1
200 MHz; accuracy 0.001%. Tektronix Type 184 Time-Mark
dB/dB; output impedance 50 Ω. Suggested equipment:
Hewlett-Packard 612A UHF Signal Generator, 450 MHz
3. Audio Signal Generator: Frequency range 10 Hz to
to 1230 MHz.
1 MHz, variable output amplitude at least 10 volts peak to
peak, accuracy 3%. General Radio Model 1310A or
Hewlett-Packard 8614A UHF Signal Generator, 800 MHz
Hewlett-Packard Model 241A.
to 2400 MHz.
4. VHF Signal Generator: Frequency range 10 MHz to 400
Hewlett-Packard 8616A UHF Signal Generator, 1800 MHz
MHz, accuracy 1%, calibrated variable output 0 to 120
to 4500 MHz.
dBm. Hewlett-Packard Model 608D.
Polarad 1107 Microwave Signal Generator, 3.8 GHz to
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
Hewlett-Packard 626A SH F Signal Generator, 10.0 GHz
dB to 90 dB (below 1 GHz). Hewlett-Packard Type 355C and
to 15.5 GHz.
355D Step Attenuators.
7. Harmonic Generator: Tektronix Calibration Fixture
Hewlett-Packard 628A SHF Signal Generator, 15.0 GHz
to 21.0 GHz.
Hewlett-Packard 938 Frequency Doubler set, 18.0 GHz to
8. 200 MHz Trap: Tektronix Calibration Fixture 067-0595-00.
9. Two (2) GR to BNC male adapters: Tektronix Part No.
Hewlett-Packard 940 Frequency Doubler set, 26.5 GHz to
10. Clip lead adapter, BNC. Tektronix Part No. 013-
Hewlett-Packard X281 Wave-guide to coaxial adapter.
11. Termination, 50 Ω, BNC. Tektronix Part No. 017-0049-
Hewlett-Packard NP292A Wave-guide to coaxial adapter.
Supplied with accessories kit.