CALIBRATION
Introduction
to peak, accuracy 3%. General Radio Model 1310A or
Hewlett-Packard Model 241A.
This spectrum analyzer is a stable laboratory instrument
4. VHF Signal Generator. Frequency range 10 MHz to
which should not require frequent recalibration. Perform-
400 MHz, accuracy 1%, calibrated 0 to -120 dBm, vari-
ance however, should be checked os directed in Section
able output. Hewlett-Packard Model 608D.
5, approximately every 1000 hours of operation or every six
months if used intermittently. This assures proper apera-
5. Constant Amplitude Signal Generator. 1 MHz to 10
tion or indicates the section of the instrument that needs
MHz amplitude 1 V to 5 V peak to peak. Tektronix Type
calibration.
191 Constant Amplitude Signal Generator.
This calibration procedure is arranged so the instrument
6. Variable Autotransformer. Voltage range 96 to 137
can be checked and calibrated with the least interaction of
(192 to 274) volts nominal line. Monitor output voltage with
adjustments and reconnecting of test equipment. A single step
can usually be performed, provided interaction between
Metered Variac.
steps and adjustments is considered.
7. Multimeter. Minimum sensitivity 20,000 Ω /volt, accuracy
CAUTION
within 1% at 10V, 12V, 125V and 3750V; ammeter range
Removing or replacing the dust cover for the
to 1 ampere, Simpson Model 262 or Triplet Model 630-PL.
instrument may be hazardous. Remove or replace
8, Step Attenuators. 1 dB and 10 dB steps, accuracy 1.5
the cover as follows: Place the accessory cover
db to 90 dB (below 1 GHz)1. H e w l e t t - P a c k a r d T y p e 3 5 5 C
(front) on the instrument. Set the instrument on
and 355D Step Attenuators.
the front-panel cover (do not set the instrument
on the front-panel controls). The dust cover may
9. Harmonic Generator. Tektronix Calibration Fixture 067-
now be removed or replaced with safety and ease.
0594-00.
Recommended Equipment
10. 200 MHz Trap. Tektronix Calibration Fixture 067-0595-
00.
The equipment required to calibrate the Type 491 is listed
in three groups: 1. Basic equipment: Check and calibrates
11. Adapter Cable. BNC female to subminiature female,
the Type 491 except for the following; sensitivity, system
4 inches. Tektronix Part No. 175-0321-00. Subminiature
flatness, front-end calibration, and the honeycomb assemblies.
to BNC male, P6041 probe cable, Part No. 010-0164-00.
2. Equipment required for checking the honeycomb assembly.
12. Two (2) GR to BNC male adapters. Tektranix Part No.
3. Equipment required to check the system sensitivity and
017-0064-00.
calibrate the local oscillator and mixer sections.
13. Clip lead adapter, BNC. Tektronix Part No. 013-0076-
The calibration of the honeycomb, local oscillator and
00.
mixer sections is complex and requires special skills and
equipment. We recommend returning these assemblies to
14. Termination, 50 Ω, BNC. Tektronix Part No. 017-0083-
Tektronix for recalibration. See the Maintenance section
01.
for instructions concerning removal of these assemblies.
15. B N C T c o n n e c t o r . T e k t r o n i x P a r t N o . 1 0 3 - 0 0 3 0 - 0 0 .
Minimum test equipment specifications are listed. If sub-
16. Two (2) BNC coaxial cables, 50 Ω. Tektronix Part No.
stitute equipment is used, it must meet or exceed specifica-
012-0057-00.
tions of the recommended equipment. Proper dial and equip-
ment setups of the substitute equipment must be determined
17. 10 dB attenuator pad2, type N fitting. Tektronix Part
by the user. Signal generators should be relatively free of
No. 011-0085-00.
harmonic content to provide a clean display.
18. 20 dB attenuator pad2, type N fitting. Tektronix Part
Group 1
No. 011-0086-00.
1. Test Oscilloscope and Vertical Plug-In Unit with 1
19. 40 dB attenuator pad2, type N fitting. Tektronix Part
and 10 probes. Minimum sensitivity .005 V/cm, frequency
No. 011-0087-00.
response DC to 30 MHz. Tektronix Type 540 Series oscillo-
scope with Type 1A1 Plug-In Unit and Tektronix P6010 ( 1 0 )
and P6011 (1) test
1
Accuracy of the IF ATTEN dB selectors is checked at the factory to
probes.
insure they are within the 0.1 dB/dB specification. Change in this
2. Time-Mark Generator. Marker outputs, .5 s to .1 s and
tolerance should be large and due to component failure. Step at-
tenuators with rigid specifications are therefore not recommended,
however, if the user desires to precisely check the attenuator error,
accuracy 0.001%. Tektronix Type 184 Time-Mark Generator.
he must either accurately calibrate the recommended equipment or
use attenuators with more rigid specifications.
3. Audio Signal Generator. Frequency range 10 Hz to
1 MHz, variable output amplitude to at least 10 volts peak
2
Supplied with accessories kit.
6-1
Calibration
will
be
performed
in
the
AN/TSM-35V5
maintenance
shelter.
Note.
