Marconi Instruments 2382 User manual

marconi
instruments
2382/2380
100HZ-400MHZ SPECTRUM
ANALYZER AND DISPLAY
Manual

Operating Manual
Prov
Sep«
H52382-900A
Vol. 1
100 Hz -400 MHz SPECTRUM ANALYZER and DISPLAY
2382/2380
Comprising:
100 Hz -400 MHz Spectrum Analyzer Type 2382
(Code No* 52382-900A)
and
Display Type 2380
(Code No. 52380-900E)
^^Harconl Instruments Ltd. 1985
Printed in the UK
Part No. 46881-489W
Print code: 8-9/85, MI 1.3c
4
85 Paee I

H52382-900A
Vol. I
CONTENTS
PEELIKINARIBS
Title page
Contents
Notes and Cautions
CHAPTERS
1General information
2Installation
3Operation
4-1 Brief technical description
4-2 Technical description
5Maintenance
6Replaceable parts
7Servicing diagrams
These chapters are
contained in a separate
volume available as an
optional accessory*
HAZARD WARNING SYMBOLS
The following symbols appear on the equipment:
Symbol Type of hazard Reference in manual
AStatic sensitive device Page (iv)
ADangerous voltages present Page (111)
ASupply voltage Page (111)
Note
Each page bears the date of the original issue or the code number and
date of the latest amendment (Am. Am. 2etc.). The title page always
shows the amendment status of the manual. New or amended material of
technical importance introduced by the latest amendment is Indicated by
triangles positioned thus Ato show the extent of the change.
When achapter is reissued the triangles do not appear.
Any changes subsequent to the latest amendment state of the manual are
included on Inserted sheets coded Cl, C2 etc.
page 11 July 85

H52382-900A
Vol. 1
NOTES AND CAUTIONS
ELECTRICAL SAFETY PRECAUTIONS
This equipment is protected in accordance with lEC Safety Class 1. It
has been designed and tested according to lEC Publication 348 «^Safety
Requirements for Electronic Measuring Apparatus^) and has been supplied in a
safe condition* The following precautions roust be observed by the user to
ensure safe operation and to retain the equipment in asafe condition*
Defects and abnorul stresses
Whenever it is likely that protection has been Impaired, for example as a
result of damage caused by severe conditions of transport or storage, the
equipment shall be made inoperative and be secured against any unintended
operation*
Removal of covers ^
Removal of the covers is likely to expose live parts although reasonable
precautions have been taken in the design of the equipment to shield such
parts. The equipment shall be disconnected from the supply before carrying
out any adjustment, replacement or maintenance and repair during which the
equipment shall be opened. If any adjustment, maintenance or repair under
voltage is Inevitable it shall only be carried out by askilled person who Is
aware of the hazard Involved*
Note that capacitors Inside the equipment may still be charged when the
equipment has been disconnected from the supply* Before carrying out any
work inside the equipment, capacitors connected to high voltage points should
be allowed to discharge through the bleed resistors fitted for the purpose;
do not attempt to remove the safety covers from the power supply until the
lamp under the top cover stops blinking* Should the unit be reconnected to
the supply with the safety covers removed and then disconnected, do not
attempt to discharge the power supply unity's main reservoir capacitors using a
shorting link as the equipment may be damaged* Discharge should always be
allowed to occur gradually*
Note also that the 12 kV e.h.t* circuit for the cathode ray tube retains
its charge for aconsiderable time after switch off. Therefore before any
handling is carried out in the vicinity of the cathode ray tube or e.h.t. unit
it is essential that the supply Is disconnected from the instrument and the
final anode lead Is shorted to the chassis several times immediately after
unplugging. The residual charge on the c.r.t. itself must also be removed by
shorting the anode connection to ground*
AC supply plug ^
The supply plug shall only be inserted in a socket outlet provided with a
protective ground contact. The protective action shall not be negated by the
use of an extension lead without protective conductor. Any Interruption of
the protective conductor inside or outside the equipment is likely to make the
equipment dangerous.
July 85 Page lit

H52382-900A
Vol. 1
Puses ^prlaary and secondary
Note that there is asupply fuse In both the line and neutral wires of
the supply lead* If only one of these fuses should rupture »certain parts of
the equipment could remain at supply potential.
To provide protection against breakdown of the supply lead, its
connectors, and filter where fitted, an external supply fuse (e.g. fitted In
the connecting plug) should be used in the live lead. The fuse should have a
continuous rating not exceeding 6A.
Make sure that only fuses with the required rated current and of the
specified type are used for replacement. The use of mended fuses and the
short-circuiting of fuse holders shall be avoided.
Anumber of secondary fuses are fitted to boards in the upper and lower
units. For details of both primary and secondary fuses refer to Performance
data -Chap. 1.'
CAUTION; STATIC SENSITIVE COHPONENTS
Components identified with the symbol Aon the circuit diagrams and/or
parts lists are static sensitive devices. The presence of such devices is
also indicated In the equipment by yellow discs, flags or labels bearing the
same symbol. Certain handling precautions must be observed to prevent these
components being permanently damaged by static charges or fast surges.
(1) If a printed board containing static sensitive components (as indicated
by awarning disc or flag) is removed, it must be temporarily stored in
aconductive plastic bag.
(2) If astatic sensitive component is to be removed or replaced the
following anti-static equipment must be used.
Awork bench with agrounded conductive surface.
Metallic tools grounded either permanently or by repeated discharges.
Alow-voltage grounded soldering iron.
Agrounded wrist strap and aconductive grounded seat cover for the
operator, whose outer clothing must not be of man-made fibre.
(3) As a general precaution, avoid touching the leads of astatic sensitive
component. When handling anew one, leave it in its conducting mount
until it is required for use.
(4) If using afreezer aerosol in fault finding, take care not to spray
programmable ICs as this may affect their contents.
WARNING: Hi^ODLING HAZARDS
This equipment is formed from metal pressings and, although every endeavour
has been made to remove sharp points and edges, care should be taken,
particularly when servicing the equipment, to avoid minor cuts.
Page iv July 85

H52382-900A
Vol. 1
Cathode ray tube: When exposing or handling the cathode ray tube care must be
taken to prevent implosion and possible scattering of glass fragments*
Handling should only be carried out by experienced personnel and the use of
safety mask and gloves is recommended* Adefective tube should be disposed
of in asafe manner by an authorized waste contractor*
WARNING: TOXIC HAZARD
Many of the electronic components used in this equipment employ resins and
other chemicals which give off toxic fumes on incineration. Appropriate
precautions should therefore be taken in the disposal of these items*
July 85 Page V

H523«2'-')00A.
Vol. 1
Chapter 1
GENERAL INFORHATION
CONTENTS
Para, Page
Features ••• ••• ,,, ••• »•» ••• ••• 2
1General
6The display
8The preset" mode
9The six mode horizontal scale
13 Amplitude measurements
16 Markers
19 Further highlights
20 Store/recall
21 Small signals
23 .Limit mask
24 Tracking generator
26 Intermodulatlon products
28 Overload protection
29 More detail
Performance data q
32 Frequency q
Measurement range
Frequency span
Frequency standard
Reference frequency
Markers
Resolution
Stability
Spectral purity
33 Amplitude ,,, ^ ^ ^
Measurement range
Displayed range
Display fidelity
Reference level
Frequency response
RF Input
Markers
Dynamic range
34 Sweep ig
Trigger source
Trigger mode
Sweep mode
Sweep time
35 Tracking generator 21
Tracking generator output
36 Display ••• ,,, ,,, 21
Display size
Trace
37 Remote operation (GPIB) 23
User accessible display
Service requests
Transfer formats
Transfer times
GPIB PLOT
July 85 Chap, i
Page 1

H52382-900A
Vol. 1
CONTENTS (continued)
Para
38
39
40
41
# # ### # Other featarea
STD 10 MHz output
47.4 MHz output (l.f. output)
Phones (Demodulated output)
Probe supply
Radio frequency Interference
Safety
Rated range of use
Conditions of storage and transport
Power requirements
Fuses
Dimensions &Weight
Options #•« •«
Beeper
Analog pen plot
Video output
RGB outputs
Versions «
•
2380 Display
2382 100 Hz-400 MHz Spectrum Analyzer
Access orles
Supplied accessories -2380 Display
Supplied accessories -2382 Spectrum Analyzer
Optional accessories -2380/2382
a#
•m•• a
• • a a• • • a
a•a• sa•
Page
24
28
28
Fig.
1The 100 Hz -400 MHz spectrum analyzer ..
2Typical spectrum analyzer resolution ••
3Typical SSB noise vs offset from carrier
4Optimum dynamic range ••• ... •«
5Typical sensitivity vs input frequency ..
3
12
13
17
18
20
FEATURES
General
1. The 2382 Fig. 1Is an exceptionally versatile general purpose spectrum
analyzer for use from 100 Hz up to 400 MHz. Although simple to operate It
has many functions which make it an Indispensable tool In research,
development, production, Installation, commissioning and maintenance. It
analyzes signals by separating them Into their frequency components and the
power or voltage level of each Is displayed as afunction of frequency, on a
c.r.t. Further facilities such as the display of amodulated signal, the
recovery of amodulating signal, the provision of atracking generator etc.
are also available.
2. The design of the 2382 incorporates many original and sophl st 1cated
features. This extends Its application In areas such as :
•Testing of h.f. and v.h.f. transmitters and receivers
•Interference monl torlng
Chap. 1
Page 2Sep. 85

I
H52382-900A
Vol, 1
July 85
Fig. 1The 100 Uz -400 MHz Spectrum Analyzer
Chap. 1
Page 3

H52382-900A
Vol. 1
Surveiilance
Signal source purity measurements
•Commissioning communication systems
•PCM and FDM system measurements
Measurements on CW, FM, and AM signals including :
non-linear modulation
hum sidebands
spurious FM on AM
carrier frequency
modulation frequency
deviation/modulation depth
•Displaying the characteristics of active and passive networks -
filters, amplifiers etc*
3. The instrument is amicroprocessor controlled swept tuned analyser of the
superheterodyne type* It comprises alower unit (2382) containing afre-
quency synthesizer and swept receiver, and an upper unit (2380) containing the
display, digital processing and power supply* The c*r*t. has aviewing area
of 140 mm x110 mm. Aminimum of multifunction front panel controls have
been used for simplicity and ease of operation*
4, The display is scaled In both frequency and amplitude for absolute and
relative measurement -advanced circuit design, digital error correction and
automatic self calibration give areference level accuracy of il dB,
5* For optimum control the operator may set the reference frequency, span,
and reference level using either akeypad or dedicated rotary controls* Full
GPIB talk and listen facilities are also provided*
The display
6* Two memory stores designated Aand Brecord the display, and the content
of either or both stores refreshes the horizontally scanned TV type raster.
The graticule, having 10 x 10 major divisions and five vertical and horizontal
minor sub-divisions, is electronically generated and the Aand Btraces can be
displayed against this background* The two traces Aand B, and the graticule,
have separate brightness controls to highlight one trace against the other or
against the graticule lines* In addition each trace may be Infilled or
outlined, according to user preference, to clarify the picture when the signal
is particularly complex. All these ensure that the display Is clear and easy
to Interpret and if the ''Options^ board is fitted it can be shown in colour on
an RGB video monitor by coupling this into asocket at the rear of the 2380*
7. The Aand Btraces have independently variable reference levels and
vertical scales* The levels relating to each are displayed adjacent to the
major graticule lines; those for the Atrace are on the left hand side of the
screen and those for the Btrace on the right hand side. Main control
settings are indicated as screen annotations not only for ease of operation
but also to provide an unambiguous photographic record if required. The
display can be protected from being overwritten by using the "SAVE"' mode.
Additional information can be typed into atext area at the top of the screen
Chap *1
Page 4July 85

H52382-900A
Vol. 1
using the Display keys. When appropriate, readout of numerical keypad entries,
menu selections, prompts, warnings and error messages are also displayed.
The ''preset'^ mode
8. Afeature which Is especially helpful to first time users is the ''preset'
mode. When this mode is selected certain keys are automatically set to
produce an 'initial' display. These keys are identifiable on the front
panel; they have green lettering. The Instrument can however be set to
switch on in any chosen setting according to operator preference. This is a
feature of the store/recall mode.
The six mode horizontal scale
9. The frequency scale of the display can be viewed in six different modes -
full, per div., meter, log, zero span and FM DEMOD* The full span mode Is
used to identify signals. By rotating the REF FREQ control adashed vertical
line bn the screen can be moved to locate arequired spectral line and the
frequency of that signal is then displayed at the bottom of the graticule
area. The 'per div.' mode can be used to 'zoom' Into that signal for amore
detailed inspection. It can be displayed at the centre, at the left or at
the right hand side of the screen as required. When METER is selected the
signal is displayed at the centre of the screen in the form of avertical
bar-chart readout
.
10* In 'log' mode, frequency Is displayed on alogarithmic scale. One to
seven decades are available ranging from 100 Hz to 1GHz.
11. The 'zero span' mode is used for recovering modulating signals or real
time monitoring of asingle signal -for settling tiroes etc. In this mode the
analyzer acts as afixed tuned receiver with selectable bandwldths. Amplitude
demodulated signals can thereforefbe displayed on the screen against atime
axis. The signals can also be heard by using the integral loudspeaker or ly
plugging headphones into aconnector at the rear of the RF unit. Asecond
function of 'zero span' enables FM deviation to be displayed and measured
against atime axis in the same way.
12. For ease of operation, in the 'auto' mode, filter bandwidth, sweep time
and video bandwidth are set automatically to give optimum resolution at each
choice of frequency span. Span can be varied from afull 400 MHz down to
100 Hz; 200 MHz to 100 Hz in a 1,2,5 sequence. Resolution bandwldths are
available from IMHz down to 3Hz in a1,3,10 sequence. The minimum bandwidth
3Hz filter with ashape factor of less than 11:1 ensures that line related
sidebands may be resolved without being masked by the limitation of the
filter.
Amplitude measurements
13. High sensitivity is achieved by careful r.f. and i.f. amplifier design,
the measurement range being from -150 dBm to +30 dBm with an accuracy of ±1 dB
at any frequency and at all levels. The vertical scale is swltchable in
1,2,5 steps from 10 dB/dlv. (a 100 dB display) down to 0.5 dB/div. and
amplitudes can be resolved to 0.01 dB.
14. Facilities ha'^e been Included to measure signal levels with respect to
1mW, IV, 1mV and ImV by changing the vertical scale from its preset mode
of dBm to dBV, dBmV, or dBgV. In addition relative measurements in dB can be
July 85 Chap. 1
Page 5

H52382-900A
Vol. 1
made# Frequency response is i0#4 dB for r.f. attenuation of 10 dB or more on
all displayed ranges#
15# Voltage ranges are available on alinear or alogarithmic display# Lin-
ear ranges extend from 100 nV/div# to 500 mV/div# in a1,2,5 sequence on a10
division graticule; log# ranges from 100 nV to 10 V (top of scale) in a
1,10,100 sequence on atwo and ahalf decade graticule#
Markers
16# Using arotary control on the front panel, markers can be steered across
the trace, providing amplitude and frequency readouts on either the A or B
display. Alternatively, by key control, amarker can be Immediately directed
to the peak of the largest signal on the display, and then Co subsequent peaks
as required# The amplitude and frequency of each peak is clearly displayed#
17# For closer inspection of an identified peak, it can be positioned at the
dashed reference frequency line and at the top of scale reference level ready
for further an'alysis by use of Che MKR 1SETS, REP FREQ and REF LEVEL keys#
Frequency can be measured Co an enhanced resolution of Hz if required by
using RES IHz (2ND FUNCT then PRBQ COUNT)# The ^signal track"' mode Is
useful in this instance as it maintains the signal at Che centre of Che screen
against the effects of possible drift -intermediate sweeps are taken In order
to achieve stability#
18. Asecond marker enables the difference In level and frequency between two
signals to be measured, for example when displaying modulation sidebands,
IntermodulaClon products or harmonic distortion#
Further highlights
19. Although information is provided in much greater detail In Chap# 3-
^Front panel control functions' there follows avery J)rief description of some
of the more significant features of Che 2380/2382 not yet discussed.
20# Store/recall #Nine sets of instrument mode settings can be permanently
stored and recalled as required#
21. Small signals# Low level signals which are often obscured by noise can
be measured very effectively by either video filtering, video averaging or by
reducing input attenuation# The former requires avery slow sweep to achieve
results but when using video averaging, changes in noise smooching can be seen
almost immediately enabling the low level signals to be Identified and
measured with speed and accuracy#
22# In an unscreened environment the c.r.t# can be switched off entirely
whilst asweep is taken and stored# This reduces electro-magnetic radiation
to aminimum and enables alow level signal measurement Co be made more accur-
ately# Subsequently the display can be switched on again to observe the
readings#
23. Limit mask# Using the data keypad and terminator keys, upper and lower
limit boundaries can be entered into the 'B' store and displayed on the screen
to provide ago/no go limit mask# This can be employed to check the
frequency response of afilter, for example, against upper and lower limits
overlaid upon it#
Chap# 1
Page 6July 85

H52382-900A
Vol. 1
24t Tracking generator «The Integral tracking generator produces asignal
whose frequency precisely tracks the spectrum analyzer tuning in all scan
modes. On full span the frequency range is therefore 100 Hz to 400 MHz,
accurate to within tl Hz of the tuned frequency*
25« The tracking generator can be used to provide the sweeping signal for
measuring the response of afilter or crystal etc* Output level Is
controllable from -9*7 to —20*3 dBm in 0*1 dB steps and a''normalize'^ feature
Is provided to compensate for frequency response errors introduced by the test
fixture, connecting leads and the analyzer Itself*
26* Interaodulation products* Normally, in the ^auto"' mode, the r*f* atten-
uator Is set to give optimum dynamic range by maintaining the signal level at
the input to the first mixer such that internally generated Intermodulation or
distortion products, produced by the non-linear behaviour of the input mixer,
do not appear greater than the noise level* When the r»f* attenuator is con-
trolled manually however overloading can occur and distortion products can be
produced*
27. Asimple key operation (INTMD IDENT) identifies these products quickly
and easily thereby giving Increased confidence in measurements. If the
amplitude of some of the displayed peaks changes when the key Is operated
these are the Intermodulation or distortion products. If amplitudes do not
change there is no distortion present*
28, Overload protection* The maximum Input signal level which can be applied
without fear of damage is +27 dBm (0*5 W) but the instrument Is protected
against accidental application of overload power up to +47 dBm (50 W) by means
of alatching relay which operates even If the Instrument is turned off. An
indication that an overload has occurred is given by the word ''OVERLOAD^'
appearing on che screen and, if the ’"OPTIONS"' board is fitted, an audible
sound being emitted from abeeper. Providing the overload is no longer pre-
sent the latching relay can be reset by pressing aspecific key on the front
panel.
More detail
29,
Complete information on all the features of the 2382, some of which are
listed below, are In Chap* 3, Front panel control functions.
Max hold
Incremental keys
Trace exchange
Trace arithmetic
The pen plot option
Meter mode
Identify refresh
Secret key
July 85 Chap, 1
Page 7

H52382-900A
Vol. 1
•Single shot
•Triggering
30. External standard, setting Internal standard, probe, and standard 10 MHz
output are covered in the introductory paragraphs of Chap. 3.
31. One of the most Important features of this analyzer is that It can be
operated remotely via the GPIB, full details of this facility are given in the
GPIB Operating manual (H 52382-900A Vol. lA).
Chap. 1
Page 8July 85

H52382-900A
Vol. 1
PERFORMANCE DATA
32. FREQUENCY
Measureaent range
Frequency span
FULL span]
l/DIVl
ZERO SPAN
METER
I
100 Hz to 400 MHz in IHz steps set by means of
keypad, dedicated rotary control or dedicated
REF FREQ keys. Usable dovn to 50 Hz.
0to 400 MHz spanning the 10 division display,
selected by FULL SPAN key.
10 Hz/div to 20 MHz/div in a1,2,5 sequence and
40 MHz/div selected by means of keypad or
dedicated rotary switch. Displayed accuracy ±1%
of separation frequency, -1% of full span.
1to 7decade logarithmic display. User selects
Start and Stop frequencies (decade values only)
and instrument selects filter bandwidths and
sweep speeds for each decade for optimum display.
For optimum display refresh, the highest fre-
quency decade is swept first. Displayed accuracy
±5 N% where Nis the number of decades selected.
Displays the amplitude modulation of any signal
at the current reference frequency against atime
axis. See Sweep section for specificat Jon.
Selection of this mode executes asingle sweep
and leaves a''bar chart"* type display at the
screen centre, whose amplitude Indicates the
instantaneous signal level at that frequency.
Measurement frequency changed with MARKERS MOVE
control. For frequency accuracy, see Marker
section.
FM DEMODj
[2nd FUNCT
ZERO SPAN]
Frequency standard
Displays the instantaneous frequency deviation
of asingle sinusoid against atime axis. This
signal must be free from significant amplitude
modulation since filter slope detection is used
as the discriminator. See Sweep section for
sped ficatlon.
Internal standard The internal standard is aTCXO type with zero
warm-up time.
Temperature stability Better than ±2 parts in 10^ over O^C to 50^C.
Aging rate Less than ±1 part in 10^ per year.
External adjustment The Internal standard can be adjusted by means of
arear panel preset (SET INI STD). The annota-
tion INT STD is shown in reverse video on the
display when the internal standard has been
adjusted.
Sep. 85 Chap. 1
Page 9

H52382-900A
Vol. 1
para. 32 (continued)
Ex ternal standard input
IEXT STD I
Input connector
Reference frequency
FULL SP^
LOG I
IZERO span] ,I'i^terI &
FM DEMODi
IsYg track
System will automatically switch to an external
standard if a signal of 1,2,5 or 10 MHz is
applied at alevel of between -15 dBm and +15
dBm. The frequency must be within ±1 part in
10^ for the system to lock. The annotation EXT
STD is shown on the display when lock is
achieved.
50 n BNC female.
Adashed vertical line may be moved across the
display by operation of the keypad, REF FREQ
rotary control or ++ keys. The frequency of any
signal on the display can be read to aresolution
of better than 1MHz. This facility permits
signal selection made in this mode to be
displayed at the reference frequency in any
subsequent /DIV selection.
Reference frequency can be positioned at the
centre, left hand or right hand side of the
display by operation of the HORIZ POSN key, the
appropriate vertical graticule line being dashed
to indicate this state. The value of the
reference frequency can be read from the screen
annotation to a resolution of t0«2!S: of span and
to an accuracy of ±{(Freq. std. error xRef.
freq./lO MKz) +2Z of selected sweep span +
oscillator drift] Hz. See ’'Stability" for
oscillator drift figures. This mode is also
selected by operation of the PRESET key.
The reference frequency rotary control is
inoperative in this mode*
Frequency accuracy as for /DIV mode but no allow-
ance is needed for oscillator drift.
Asignal at the reference frequency of the
display is tracked. The tuning of the instrument
is adjusted after every sweep to cancel out any
drift in the signal being analyzed. The only
restrictions are that the signal must be
positioned sufficiently far up the skirt of the
response to ensure capture and that the signal
drift is not so fast that the response drifts off
the display in one sweep interval. Operates only
in HORIZ POSN centre mode.
If the frequency span is rapidly reduced asingle
sweep will be taken at appropriate Intermediate
values so as not to lose track of the signal.
Chap. 1
page 10 July 85

H52382'900A
Vol. I
Markers Markers measure the frequencies of points on the
display in FULL SPAN, /DIV and METER horizontal
modes*
ABselect !Key toggles to place the markers on either the A
or Btrace*
12MOVE! &!^rT| adedicated rotary control permits amarker to be
positioned anywhere on the selected Aor Btrace*
The screen annotation displays the frequency of
the marker to the resolution and accuracy of the
reference frequency above* If both Marker 1and
Marker 2are displayed, additional screen annota-
tion shows the value of frequency difference be-
tween them to the same accuracy as in the
Frequency Span /DIV mode*
IFREQ COUNT The frequency of any spectral line viewed on the
screen may be measured by moving the marker to
the signal of interest* The resolution of the
screen readout is tlO kHz on spans greater than
200 kHz/divlslon, il Hz on spans of less than 200
Hz/dlvlsion and ilOO Hz for all other spans*
Accuracy as for Frequency Standard* Restrictions
are chat the selected filter must have a3dB
bandwidth greater than 0*2% span; that only one
signal is present in this bandwidth and that the
marker must be at least 20 dB out of the noise up
the filter skirt*
[RESIH^
(2nd FUNCT
FREQ COUNT)
(peak find
next' peakI
(2nd FUNCT
PEAK FIND)
As for FREQ COUNT except resolution is 1Hz
for all spans*
Marker 1positions itself on the peak of the
largest signal on the display and annotation
gives this frequency to /DIV accuracy. This
value may be transferred to the reference fre-
quency or Che incremental frequency by use of the
MKRl SETS keys.
Asimilar function to PEAK FIND except that the
marker moves to successively lower amplitude
peaks up to amaximum of 9peaks*
MKRl SETS REF FREQ Operation of this key sets the reference fre-
quency to that of the Marker 1frequency.
MKRl SETS INC FREQ] Operatl on of this key sets the incremental
frequency step to be that of the Marker 1
frequency*
AF SETS INC FRE^ Operation of this key sets the incremental
frequency step to be that of the difference
between Marker Iand Marker 2frequencies.
July 85 Chap* 1
Page 11

H52382-900A
Vol. 1
para. 32 (continued)
Resolution
Resolution bandwldths Twelve filters with 3dB bandwidths of 3Hz to
IMKz In a1»3>10 sequence. Optimally selected for
chosen span In AUTO mode or manually selected by
dedicated keys. Refer to Fig. 2.
Accuracy 3dB points within ±20% of their nominal value
apart from the 1MHz filter which Is •^0% -30%.
Shape factor All bandwidths have askirt selectivity for 60 dB/
3dB points of less than 11:1. All filters (apart
from the 1MHz filter) are synchronously tuned five
pole Gaussian shaped filters.
1MHz filter shape factor is less than 5:1.
Frequency
Fig. 2Typical spectrum analyzer resolution
Stability
Residual FM Less than 1.5 Hz peak-to-peak during a10 speriod
for spans narrower than 20 kHz, resolution
bandwidth of 30 Hz or less and video bandwidth of
43 Hz or less.
Drift After a1hour warm-up the LO drift rate Is as
follows:
<10 Hz/mln at 10 Hz/dlv» increasing to
<20 Hz/raln at 2kHz/dlv.
<500 Hz/mln at 5kHz/dlv. increasing to
<1 kHz/raln at 200 kHz/dlv.
<50 kHz/mln at 500 kHz/dlv. Increasing to
<100 kHz/mln at 40 MHz/dlv.
Chap. 1
Page 12 Sep. 85

H52382-900A
Vol. 1
para« 32 (continued)
The drift Is not cumulative; the oscillators are
reset every 10 seconds or during each sweep
ret race »whichever Is the longer#
Spectral purity
Coherent sidebands Better than -83 dBc using 3Hz filter.
(** UNDER REVIEW*^)
Displayed noise
sidebands At 100 MHz:
Offset from Displayed noise
carrier (normalized to
bandwl dth)
too Hz <-90 dBc
300 Hz <-95 dBc
20 kHz <-100 dBc
Frequency otfseC
Flg» 3Typical SSB noise vs offset from carrier
33. AHPLITUDE
Measurement range —150 dBm to +30 dBm; 100 nV/dlv to 500 mV /dlv.
Overload protected to +47 dBm (50W) by means of a
latching relay which can be reset using INTMD
IDENT key.
Sep. 85
Chap. 1
Page 13

H52382-900A
Vol, 1
para. 33 (continued)
Displayed range
IdB/DIVISiM
VOLTS/DIVI
LOG VOLTS I
f2nd FUNCT
VOLTS/DIV)
Display fidelity
VOLTS/DIV
LOG VOLTS
Reference level
dB/DIVISION
Input protection may be overridden If required by
means of an unlabelled second function for use on
pulsed r.f. signals. Input is protected when
Instrument is switched off.
Two channels of display, A and B, may be selected
so that either can display any compatible range,
at any reference level, with separate annotation
down each side of the display.
The Aand Bdisplays can be Independently set to
give any of the ranges listed:
100 dB at
50 dB at
20 dB at
10 dB at
5dB at
10 dB/div.
5dB/div.
2dB/div.
IdB/div.
0.5 dB/div.
Range selection is by means of dedicated keys and
can be made on both live or stored displays.
Expansion is around the reference lesrel at the
top of the graticule.
On stored displays, one vertical scale higher and
one vertical scale lower may be recalled and
displayed.
Electronic graticule is changed to give two and
ahalf decades of logarithmic display calibrated
at each decade boundary In units of volts.
Departure from true logarithmic relationship less
than 0.3 dB anywhere over the top 80 dB of the
display.
Typically less than 0.05 dB per dB.
Linearity of display less than 12% f.s.d.
Departure from true logarithmic relationship less
than ±3% of measured value anywhere over the
display.
-150 dBm to +30 dBm in 0.025 dB (average) steps
or equivalent In dBV, dBmV or dByV. The level
may be set with either the keypad, dedicated
rotary control or the dedicated It REF LEVEL
keys. A dB relative mode sets the top of the
Chap. 1
page 14 July 85