Tektronix 7L5 Manual

*TB 9-6625-2005-35
SUPERSEDED COPY DATED 24 APRIL 1981
DEPARTMENT OF THE ARMY TECHNICAL BULLETIN
CALIBRATION PROCEDURE FOR
SPECTRUM ANALYZER
TEKTRONIX, TYPE 7L5 (PL-1391/U)
W/PLUG-IN L1 AND L3
Headquarters, Department of the Army, Washington, DC
16 June 1988
Approved for public release; distribution is unlimited.
REPORTING OF ERRORS
You can help improve this publication by calling attention to errors and by recommending improvements
and stating your reasons for the recommendations. Your letter or DA Form 2028, Recommended
Changes to Publications, should be mailed directly to Commander, U.S. Army TMDE Support Group,
ATTN: AMXTM-LPP, Redstone Arsenal, AL 35898-5400. A reply will be furnished directly to you.
Paragraph Page
SECTION I. IDENTIFICATION AND DESCRIPTION
Test instrument identification........................................................... 1 2
Forms, records, and reports............................................................. 2 2
Calibration description..................................................................... 3 2
II. EQUIPMENT REQUIREMENTS
Equipment required......................................................................... 4 3
Accessories required....................................................................... 5 3
III. CALIBRATION PROCESS
Preliminary instructions ................................................................... 6 5
Equipment setup............................................................................. 7 6
Readout verification (L3 plug-in only)................................................ 8 7
Calibrator frequency and amplitude.................................................. 9 7
Sweep triggering............................................................................. 10 10
Dot frequency range and accuracy................................................... 11 11
Display dynamic range.................................................................... 12 13
Display flatness .............................................................................. 13 16
Frequency span accuracy and linearity............................................. 14 18
Reference level accuracy (for L3 plug-in only)................................... 15 19
Sweep rate accuracy....................................................................... 16 21
Displayed frequency stability........................................................... 17 22
Final procedure............................................................................... 18 23
*This bulletin supersedes TB 9-6625-2005-35, 24 April 1981, including all changes.
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TB 9-6625-2005-35
SECTION I
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification. This bulletin
provides instructions for the calibration of Spectrum
Analyzer, Tektronix, Type 7L5 (PL-1391/U) w/Plug-in L1
and L3. The manufacturer's manual was used as the
prime data source in compiling these instructions. The
equipment being calibrated will be referred to as the TI
(test instrument) throughout this bulletin.
a. Model Variations. None.
b. Time and Technique. The time required
for this calibration is approximately 6 hours, using the
dc and low frequency technique.
2. Forms, Records, and Reports
a. Forms, records, and reports required for
calibration personnel at all levels are prescribed by TB
750-25.
b. Adjustments to be reported are
designated (R) at the end of the sentence in which they
appear. When adjustments are in tables, the (R) follows
the designated adjustment. Report only those
adjustments made and designated with (R).
3. Calibration Description. TI parameters and
performance specifications which pertain to this
calibration are listed in table 1.
Table 1. Calibration Description
Test instrument
parameters Performance specifications
Calibrator Frequency range: 500 kHz ± 1 Hz
Output voltage: - 40 dBV ±.15 dB
Display Dynamic range: Log 2 dB/DIV = 16 dB (±.15 dB/dB to 1 dB (max)
Accuracy: Log 10 dB/DIV = 80 dB (±.08 dB/dB to 2 dB (max)
Frequency
span/div Range: 50 Hz to 500 kHz Accuracy: ± 5%
Sweep timing Range: 0.01 ms to 10 s
Accuracy: ± ≥5%
Dot frequency 0 Hz to 4999.75 kHz (0° to 50°C ±20 Hz + 10-5 dot readout)
Display flatness Frequency range: 20 Hz to 5 MHz
Accuracy: ±0.7 dB (±0.8 dB for L3 plug-in)
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TB 9-6625-2005-35
Table 1. Calibration Description - Continued
Test instrument
parameters Performance specifications
Frequency
span Range: 50Hz to 500 kHz/DIV Linearity: within 5%
Accuracy: ± 5%
Sweep rate Range: 0.1 ms to 10 s
Accuracy: within 5% of rate selected
Sweep triggering Range: 30Hz to 500 kHz
Level: -1.5 div
Reference level Range L1 L3
-128 dBm to
+21 dBm (50Ω)
-139 dBm to
+10 dBm (600Ω)
Log 2 dB/DIV -128 dBm to
+21 dBm
-141 dBV to
+ 8 dB V (Hi z)
-70 dBm to
+21 dBm (50Ω)
-81 dBm to
+10 dBm (600Ω)
Log 10 dB/DIV -70 dBm to
+21 dBm
-83 dBV to
+8 dBV (Hi Z)
Incremental accuracy When calibrated at -40 dBV in log mode
L1 and L3: Within 0.2 dB/dB with cumulative error of 0.25 dB/10 dB
SECTION II
EQUIPMENT REQUIREMENTS
4. Equipment Required. Table 2 identifies the specific
equipment to be used in this calibration procedure. This
equipment is issued with Secondary Transfer Calibration
Standards Set AN/GSM-287. Alternate items may be
used by the calibrating activity when the equipment
listed in table 2 is not available. The items selected
must be verified to perform satisfactorily prior to use and
must bear evidence of current calibration. The
equipment must meet or exceed the minimum use
specifications listed in table 2.
5. Accessories Required. The accessories listed in
table 3 are issued as indicated in paragraph 4 above and
are used in this calibration procedure. When necessary,
these items may be substituted by equivalent items,
unless specifically prohibited
.
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TB 9-6625-2005-35
Table 2. Minimum Specifications of Equipment Required
Item Common name Minimum use
specifications Manufacturer and model (part number)
A1 AC VOLTMETER Frequency range: 500 kHz
Accuracy: 1% Hewlett-Packard, Model 400EL (7915906)
A2 ATTENUATOR Range: 0 to 90 dB in 10 dB steps
Accuracy: ±0.25% Hewlett-Packard, Model 355D (355D)
A3 ATTENUATOR Range: 0 to 12 dB in 1 dB steps
Accuracy: ±0.25 dB Hewlett-Packard Model 355C (79108075
A4 AUTOTRANSFORMER Range: 105 to 125 V ac
Accuracy: ±1% General Radio, Model W10MT3AS3 or Ridge, Model 9020F (7910809)
A5 DIGITAL
VOLTMETER Voltage range: 0 to 20 V dc Accuracy: ±1% Hewlett-Packard, Model 3490AOPT060
(3490AOPT060)
Dana, Model 5000, or
Dana, Model 5000, w/641
A6 FREQUENCY
COUNTER Range: 499.9995 to 500.005 kHz
Accuracy: 10-6Hewlett-Packard, Model 5345 (MIS-
28754/1 Type 1) w/5355A
A7 OSCILLOSCOPE Must be compatible with TI Tektronix, 7000 series
(to be provided by customer)
A8 OSCILLOSCOPE
CALIBRATOR Markers out: 10 ms to 10 s Ballantine, Model 6126M (MIS-28714 Type 1
A9 TEST OSCILLATOR Frequency: 10 Hz to 5 MHz
Level accuracy: 1% Hewlett-Packard, Model 652A (MIS- 10224)
A10 VERTICAL
AMPLIFIER Must be compatible with 7000 series oscilloscope Tektronix, Types 7A15, 7A16, 7A18, etc.
A11 VARIABLE
ATTENUATOR Range: 0 to 69 dB Accuracy: From test report Weinschel, Model AF117A-69-34 (AF117A-69-34)
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TB 9-6625-2005-35
Table 3. Accessories Required
Item Common name
(official nomenclature) Description (part number)
B1 ADAPTER BNC T-type, 2 jacks, 1 plug (MS35173-274C)
B2 ADAPTER BNC plug terminations (MS35176-491B)
B3 ADAPTER1N plug to BNC jack (10519457) (UG201A/U)
B4 ADAPTER BNC plug to double banana jacks (7909401) (7907592)
B5 ADAPTER1Single banana jack to alligator clip (7907560)
B6 CABLE 30-in., RG-58/U; double banana plug terminations (7907470)
B7 CABLE124-in., RG-58/U; BNC plug terminations (10519141)
B8 EXTENDER1Tektronix, Model 067-0616-00 (067-0616-00)
B9 LEAD 32-in., single banana plug to test hook (red) (7915941-1)
B10 PROBE (TEST LEAD) 36-in., BNC plug to X10 probe, Tektronix, Type P6106 (11513202-
1)
B11 TERMINATION
(DUMMY LOAD) 50-Ωfeed-through; BNC plug to BNC jack (11048B or 11048C)
B12 TEST LEAD Single banana plug to test hook (SKC-4850-14 or 7916122)
1Two required.
SECTION III
CALIBRATION PROCESS
6. Preliminary Instructions
a. The instructions outlined in paragraphs 6 and 7
are preparatory to the calibration process. Personnel
should become familiar with the entire bulletin before
beginning the calibration.
b. Items of equipment used in this procedure are
referenced within the text by common name and item
identification number as listed in tables 2 and 3. For the
identification of equipment referenced by item numbers
prefixed with A, see table 2, and for prefix B, see table 3.
c. Unless otherwise specified, verify the result of
each test and, whenever the test requirement is not met,
take corrective action before continuing with the
calibration. Adjustments required to calibrate the TI are
included in this procedure. Additional maintenance
information is contained in the manufacturer's manual for
this TI.
d. Unless otherwise specified, all controls and
control settings refer to the TI.
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TB 9-6625-2005-35
7. Equipment Setup
WARNING
HIGH VOLTAGE is used or exposed
during the performance of this
calibration. DEATH ON CONTACT
may result if personnel fail to
observe safety precautions.
NOTE
L3 plug-in switch positions are in
parenthesis.
a. Install TI into center compartments of a
4-compartment or right two compartments of a
3-compartment oscilloscope (A7).
b. Select proper oscilloscope controls to
correspond with plug-in compartments occupied by TI.
c. Connect autotransformer (A4) to oscilloscope.
d. Connect autotransformer to a 115-V ac power
source and adjust controls for a 115-V ac output.
e. Set oscilloscope power switch to on and allow
sufficient time for warmup and stabilization.
f. Position controls as listed in (1) through (15)
below: (1) DOT MKR control fully cow (detent
position). (2) FREQUENCY SPAN/DIV switch to MAX.
(3) RESOLUTION (Hz) switch to COUPLED.
(4) REFERENCE LEVEL VAR control fully
cow (detent position).
(5) BASELINE CLIPPER control fully cw.
(6) REFERENCE LEVEL LOG 10 dB/DIV
pushbutton on.
(7) REFERENCE LEVEL switch to -40 dBV.
(8) REFERENCE LEVEL INPUT BUFFER
pushbutton off.
(9) TRIGGERING SOURCE FREE RUN
pushbutton on.
(10) TRIGGERING MODE NORM pushbutton
on.
(11) DIGITAL STORAGE SAVE A pushbutton
to off. (12) DIGITAL STORAGE MAX HOLD
pushbutton off.
(13) dBm/dBV switch to dBV (plugin module
switch). (14) INPUT TERMNZswitch to 50Q (L3 plug-in
only). (15) TIME/DIV switch to AUTO.
g. Connect CALIBRATOR to plug-in INPUT using
cable (B7).
h.Only perform i through I below if L3 plug-in is
being used.
i. Position controls as listed in (1) through (8)
below: (1) LOG 2 dB/DIV pushbutton on.
(2) FREQUENCY SPAN/DIV control to 2
kHz. (3) RESOLUTION (Hz) control to 3 kHz.
(4) TIME/DIV control to 0.2 s.
(5) DIGITAL STORAGE DISPLAY Aand B
pushbuttons on.
(6) VERT POSITION control adjusted to place
display on the bottom horizontal graticule line.
(7) DOT FREQUENCY control to 500.00 kHz.
(8) LOG 10 dB/DIV pushbutton on.
j. Adjust LOG CAL control for a full screen (8
division) display.
k. Push LOG 2 dB/DIV pushbutton to on and
adjust AMPL CAL control (L3) for a full screen display.
I. Repeat i(8) through kabove until displayed
waveform is 8 vertical divisions.
NOTE
Perform m below if L1 plug-in is
being used.
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TB 9-6625-2005-35
m. Position controls as listed in (1) through (10)
below: (1) SWP CAL and HORIZ POSITION controls
adjusted until second and tenth vertical signals are
alined with second and tenth vertical graticule lines
(counted from left edge).
(2) FREQUENCY SPAN/DIV control to 2
kHz.(3) TIME/DIV control to 0.2 s.
(4) DIGITAL STORAGE DISPLAY Aand B
pushbuttons on.
(5) VERT POSITION control adjusted to
place display baseline on bottom horizontal graticule
line. (6) RESOLUTION (Hz) control to 3K.
(7) DOT FREQUENCY CONTROL to 500.00
kHz. (8) LOG CAL control for a fullscreen display.
(9) REFERENCE LEVEL LOG 2dB/DIV
pushbutton on.
(10) AMPL CAL control for a full screen
display.
8. Readout Verification (L3 Plug-in Only)
a. Performance Check
(1) Position controls as listed in (a) through
(c) below: (a)INPUT REF switch to dBm/50ΩΩ .
(b)INPUT TERMNZswitch to 50ΩΩ.
(c)REFERENCE LEVEL control for
+21 dBm.(2) Position INPUT REF switch to dBV and
observe art readout for a +8 dBV indication displayed.
(3) Position INPUT REF switch to dBm/600ΩΩ
and observe crt readout for a +10 dBm indication
displayed.
NOTE
The INPUT connector is a three-
conductor BNC connector with the
outer ring used to detect the
presence of a 10X probe.
(4) Short INPUT outer ring using adapter and
lead (B4 and B12) and observe crt readout for a 20 dB
increase.
b. Adjustments. No adjustments can be made.
9. Calibrator Frequency and Amplitude
a. Performance Check
(1) Connect equipment as shown in figure 1.
(2) Observe frequency counter (A6)
indication. If frequency counter does not indicate
between 499.999 to 500.001 kHz, perform b(1) and (2)
below. (3) Observe digital voltmeter (A5)
indication. If digital voltmeter does not indicate between
.3579 to .3746 V dc, perform b(1) and (3) through (19)
below.
b. Adjustments
(1) Remove TI from oscilloscope and
reconnect to oscilloscope using two extenders (B8).
(2) Adjust Y390 (fig. 2) for a frequency
counter indication of 500.000 kHz.
(3) Remove plug-in module from TI and place
insulating tape (e.g., scotch tape) over pins A13, B13,
A14, B14, A15, and B15 of interface connection (fig. 3).
(4) Reinsert plug-in module in T1.
(5) Connect test oscillator (A9) output (without
the termination) to ac voltmeter (A1), using cable (B7).
(6) Adjust test oscillator controls for an output
frequency of 500 kHz and 10 mV indication on ac
voltmeter.
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TB 9-6625-2005-35
Figure 1. Calibrator accuracy - equipment setup.
(7) Disconnect cable from ac voltmeter input
and reconnect to TI input.
(8) Position controls as listed in (a) through
(d) below: (a)DOT FREQUENCY control for 500
kHz. (b)FREQUENCY SPAN/DIV control for
2 kHz. (c)RESOLUTION (Hz) control to 30 k.
(d)LOG 2 dB/DIV pushbutton on.
(9) Adjust REFERENCE LEVEL control to
display signal at center of crt and note signal position
(reference).
(10) Disconnect cable from input and connect
CALIBRATOR output to input, using cable (B7).
(11) Adjust R892 (fig. 2) for a CALIBRATOR
output amplitude as noted in (9) above.
(12) Connect test oscillator output to ac
voltmeter input, using cable (B7) and termination (B11).
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TB 9-6625-2005-35
(13) Adjust test oscillator controls for an output
frequency of 500 kHz and 10 mV indication on ac
voltmeter.
(14) Disconnect termination from ac voltmeter
and reconnect test oscillator output without termination
to TI plug-in input.
(15) Adjust REFERENCE LEVEL control to
display signal at center of crt and note signal position
(reference).
(16) Remove screws to swing down IF module
assembly so pin 13 is accessible (fig. 4).
(17) Using lead and adapter (B12 and B5)
short pin (B13) (fig. 4) to chassis ground.
Figure 2. Adjustment locations.
Figure 3. Plug-in module rear connector locations.
(18) Adjust R895 (fig. 2) for a CALIBRATOR
output amplitude as noted in (15) above.
(19) Disconnect equipment setup, short, and
tape from pins.
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TB 9-6625-2005-35
Figure 4. IF module swung down to expose internal locations.
10. Sweep Triggering
a. Performance Check
(1) Turn POWER switch of oscilloscope (A7)
to off and install vertical amplifier (A10) in the left
compartment.
(2) Turn POWER switch to on and press
VERT MODE LEFT pushbutton in.
(3) Press TRIG SOURCE LEFT pushbutton in
and connect test oscillator (A9) output to vertical
amplifier CH1 input, using cable and termination (B7 and
B11). (4) Position controls as listed in (a) through
(e) below: (a)DIGITAL STORAGE pushbuttons
off. (b)FREQUENCY SPAN/DIV control for
0.
(c)TRIGGERING SOURCE NORM
pushbutton on. (d)TRIGGERING FREE RUN
pushbutton on. (e)TIME/DIV control to 10 ms.
(5) Adjust test oscillator frequency control for
30 Hz and an amplitude level of 1.5 divisions.
(6) Press TRIGGERING SOURCE INT
pushbutton on and adjust LEVEL/SLOPE control for a
stable triggered display.
(7) Adjust test oscillator frequency control for
500 kHz output and repeat technique of (6) above.
(8) Press TRIGGERING SOURCE FREE
RUN pushbutton on.
(9) Press TRIGGERING MODE SGL SWP
pushbutton and observe that a sweep is initiated on crt.
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