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8566B
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HP 8566b schematic

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Notice
Hewlett-Packard to Agilent Technologies Transition
This documentation supports a product that previously shipped under the Hewlett­Packard company brand name. The brand name has now been changed to Agilent Technologies. The two products are functionally identical, only our name has changed. The document still includes references to Hewlett-Packard products, some of which have been transitioned to Agilent Technologies.
Printed in USA March 2000
Section I
Manual Operation
Chapter 1 -GETTING STARTED Chapter 2 - DATA Chapter 3 - FUNCTION Chapter 4 - CRT Chapter 5 - TRACE Chapter 6 - MARKER Chapter 7 ­Chapter 8 - COUPLED FUNCTION
Chapter 9 ­Chapter 10 - INSTRUMENT STATE Chapter 1 1 - SHIFT Chapter 12 - USER Chapter 13 - PLOTTER OUTPUT
SCALE SWEEP
DISPLAY
AND
AND TRIGGER
KEY
DEFINED
REFERENCE LINE
FUNCTIONS
KEYS

GENERAL INFORMATION

GENERAL DESCRIPTION
GENERAL INFORMATION
The HP 8566B is a high-performance spectrum analyzer which operates from 100 Hz to 2.5 GHz in the low frequency band and 2 - 22 frequency tuning and an internal micro-computer to automate controls and provide useful operating features.
GHz
in the preselected microwave band. It uses a synthesized LO to provide accurate
HP 8566B SPECTRUM ANALYZER
The HP 8566B consists of an 85662A Display Section and an 85660B RF Section. Connect the two sections
along with the inter-connection cables as shown in the illustration below.
Connect interconnection cables as shown:
Line Module
85662A
Display Section
85660B
RF Section
Line Module.
Interconnect Cable Interconnect Cable
I
(85662-60093)
\
(85662-60094)
HP-IB
Connector
REAR PANEL CONNECTIONS
Manual Operation 1

INITIAL POWER ON

CAUTION
GENERAL INFORMATION
Before connecting the line power cords, make sure the appropriate line voltage and
line fuse have been selected for both the RF and Display sections of the analyzer. For complete information on line voltage and fuse selection, refer to the HP 8566B Opera­tor’s Handbook. For information on line power cords for a specific country, contact the nearest Hewlett-Packard office.
INITIAL POWER ON
After making the AC power line connections, the STANDBY lights of both the RF and Display section should be
on. As long as the instrument is operating (LINE ON) or in STANDBY, the accuracy specifications of the internal frequency standard will be met. After a cold start, such as on-receipt of instrument, the analyzer requires 24 hours to stabilize prior to meeting specified performance.
INSTR
LINE ON AND STANDBY
CHECK LED
Upon LINE ON, the instrument will perform an automatic internal instrument check. If one or both of the red instrument check lights (INST CHECK I and II) remain on after this brief check routine, refer to the chart below to localize the problem.
LED On
I
II

Calibration

Problem
Digital Storage failure in 85662A
Interface Failure
Controller
(A15)
Check bus interconnect cable (85662-60094) Check bus interconnect cable (85662-60094)
and check if Al2 board is connected tightly Check if Al5 is connected tightly in 85660B
and that contacts are clean.
Solution
In order to meet specified frequency and amplitude accuracy, the analyzer’s calibration must be checked periodi­cally to ensure the highest performance.
2 Manual Operation

CRT DISPLAY

5.
Maximize amplitude response with FREQ ZERO adjustment.

Error Correction Routine

A 30 second internal error correction routine minimizes uncertainties due to control changes in the analyzer. To start the routine, press
A “CORR’D” readout will appear on the left edge of the CRT upon completion of this routine. If the message “Adjust AMPTD CAL” appears in the display, repeat the manual calibration before running the error correction
routine again.
(,,,,,
W
(%?I.
GENERAL INFORMATION
CRT DISPLAY
The analyzer’s CRT display presents the signal response trace and all pertinent measurement data. The active
function area names the function under DATA control and shows the function values as they are changed. All the
information necessary to scale and reference the graticule is provided.
MARKER
Reference User display
level
annotation amplitude
frequency
Active
function
readout
/
Center Resolution
frequency
’
-
11
PF’:
BW 1
L/
bandwidth
LHX
YBW
100
I
Video
bandwidth
bun
17.wa
ass
4
CIHX
,TRACE
/TRACE
Internally
’
generated
graticule
HZ
Sweep time
span
A
B

PLOTTER OUTPUT

The trace data, graticule, and annotation on the analyzer’s screen can be directly output via HP-IB to a Packard plotter (such as the HP front pane1 of the analyzer.
4 Manual Operation
7245A/B,
7240A, 7470A, or 9872C) by pressing the LOWER LEFT key on the
Hewlett-
GENERAL INFORMATION

FRONT PANEL OVERVIEW

FRONT PANEL
OVERVI
IEW

Control Groups

1
CRT DISPLAY:
2
TRACE: 3 REFERENCE LINE: 4 SCALE:
5 KEY FUNCTION:
6 SWEEP and TRIGGER: 7
RFINPUT:
8
DATA/FUNCTION: 9
CAL OUTPUT:
10
MARKER:
11
COUPLED FUNCTION:
12
INSTRUMENT STATE:
13 LINE ON &STANDBY: 14
REORDER/PLOTTER
FUNCTIONS:
Signal response and analyzer settings
Control of signal response display Measurement and display aids Selects logarithmic or linear amplitude scale Access to special functions Selects trace update trigger
100 Hz to 22 GHz ( + 30 dBm max. power) Fundamental analyzer control Calibration signal Movable bright dot markers for direct frequency and amplitude readout Maintenance of absolute amplitude and frequency calibration by automati­cally selecting certain analyzer control settings Local
(1~1)
select key, SAVE and RECALL keys and FULL SPAN keys
Powers instrument and performs instrument check Controls output to recorder or HP-IB controlled plotter
Manual Operation 5
REAR PANEL OUTPUTS

Frequency Reference Input/Output

GENERAL INFORMATION
To lock the spectrum analyzer to an external frequency reference, set the FREQ REFERENCE switch to
EXT.
Analyzer performance will be degraded unless frequency reference phase noise and spurious signals are < - 140
dBc single sideband (1 Hz) referred to 10 MHz at a 100 Hz to 10
the spectrum analyzer internal frequency reference, set the FREQ REFERENCE switch to
Frequency Reference
Input/Output
kHz
offset. To lock another spectrum analyzer to
INT
Input/Output
External Frequency Reference Requirements:
Frequency: 5 MHz & 50 Hz
or
EXT INT
Power: 0 to 10 dBm
Input Impedance:
10 MHz ? 100 Hz
5Of2
nominal
Internal Frequency Reference Characteristics.
Frequency: 10 MHz
Power: 0 dBm
Output
impedance: 5OQ

HP-IB Input Output Connector

The Hewlett-Packard Interface Bus allows remote operation of the analyzer as well as input and output of mea­surement data. See Section II of this manual.

IF and Video Connectors

The IF and Video connectors allow the 85650A Quasi-Peak Adapter to be used with the analyzer for
EM1
measurements
NOTE
When the Quasi-Peak Adapter is disconnected from the analyzer, make sure the IF INP connector connects to the IF OUT connector with one short BNC cable, and VIDEO INP connector connects to the VIDEO OUT connector with the other short BNC cable. Failure to connect the BNC cables will result in a loss of signal.
8 Manual Operation
MAKING A MEASUREMENT
0- 2.5 GHz or 2 -22 GHz’ frequency span. Both
keys preset all the analyzer functions to automatically maintain a calibrated display during the course of the measurement.

Example

Connect the CAL OUTPUT signal to RF INPUT
Press
l%J
This presets the analyzer to a full 0- 2.5 GHz span with 0 dBm Reference level and automatically couples
al1
secondary receiver functions.
,,
e&c 0.0 d&n .Tllh
:3
&I
T
GE-l-l-ING
10
de
--_.
_
-.' t -- --' -.'
--
-.
t--
i-
STARTED
'--
--
---
and use the knob
or the numeric keyboard to t
quency
to 100 MHz. Note that the activated FUNC­TION (CENTER FREQUENCY) appears on the CRT graticule field.
Press
bl
$6
(91
or numeric keyboard to reduce the frequency
to 100
and use the knob
kHz.
, step keys
@
‘The
I’;:]
key is also activated with LINE ON.
12 Manual Operation
/
FREQUENCY
GETTING STARTED

DIRECT FREQUENCY AND AMPLITUDE READOUT

and use the knob 0, step keys
or numeric keyboard to position the peak of the
signal on the top graticule line.
The frequency and amplitude of the signal are read out from the graticule border. All secondary analyzer functions (resolution bandwidth, video bandwidth, sweep time, and attenuation) were automatically adjusted to maintain a
fully calibrated display. The coupled functions can also be uncoupled to allow manual operation.
For instance, to manually control the resolution bandwidth, press (::‘1 and change bandwidth with any combina-
tion of DATA control. The above also applies to I’:“:“) , @ ,
c)
0
.-. -.
LEVEL
.-
lzxrEu a...e.. m*
[,,,.)
, or
Pf5
ml 1
[‘::::‘1
I1 I I I
.“I
wn 3 L”,
SW’
I1
1..
5pbN
3ae
Il..=
DIRECT FREQUENCY AND AMPLITUDE READOUT
.“I
Markers can be used to quickly identify signal frequency and measure signal separation or amplitude differences.
Activate a marker 02 the display with NORMAL. Tune marker with 0 . tude of the signal are read out with the marker.
To measure the harmonic(s) of the signal, press A and tune the second marker to the signal’s harmonic. The frequency separation and amplitude difference are read out.
The frequency and ampli-
amplitudes
-delta
(A) markers are available to
SAVE/RECALL GETTING STARTED

SAVE/RECALL

The HP 8566B instrument control settings can be saved in an internal memory and later recalled to make a measurement.

SHIFT KEYS

In addition to the front panel functions listed on the keys, another set of functions can be assigned to the same keys by pressing the blue B key prior to activating a front panel key. These will be covered in more detail in Chapter
11.
[/
[I(c1111 m
to
0
6
provide access to the six internal storage registers.

AUTOMATIC MEASUREMENTS

The HP 8566B is fully programmable via the Hewlett-Packard Interface Bus (HP-IB) -HP’s implementation of IEEE STD 488-1975. Internationally, HP-IB is in concert with the IEC main interface document.
A computing controller/calculator can be used with the HP 8566B to configure an automatic measurement system. Just as the analyzer’s front panel is keyed manually to control functions and change values, simple program codes are transmitted via the HP-IB with a controller to make measurements automatically These pro­gram codes are listed in the Remote Operation section of the instrument pull-cards.
Detailed information on remote operation is found in Section II of this manual.
14 Manual Operation
DATA

DATA CONTROLS

CHAPTER 2
DATA

GENERAL DESCRIPTION

DATA controls are used to change function values for functions such as center frequency, start frequency, resolu-
tion bandwidth, or marker position.
DATA CONTROLS
The DATA controls are clustered about the FUNCTION keys which “call up” or activate the most frequently used
spectrum analyzer control functions: center frequency, frequency span (or start/stop frequency), and reference
level. The other functions that accept DATA control are shown below:

FRONT PANEL FUNCTIONS USING DATA CONTROLS

To the left of the FUNCTION Keys are the Data knob 0 and the DATA STEP keys to make incremental changes to the activated function. To the right of the FUNCTION keys is the DATA number/
units keyboard which allows changes to an exact value.
@ @
, which are used
Manual Operation 15

DATA ENTRY READOUT

The DATA controls will change the activated function in a manner prescribed by that function. For example, center frequency can be changed continuously with the DATA knob 0 , with the DATA STEP keys @ a , width, which can be set only to discrete values, can still be changed with any of the DATA controls. The DATA knob 0 and DATA STEP keys 13
from the number/units keyboard which may not coincide with an allowable bandwidth will select the nearest bandwidth.
or set exactly with the DATA number/units keyboard. Resolution band-
61
increment the setting from one bandwidth to the next. An entry
or in steps proportional to the frequency span
DATA
DATA ENTRY READOUT
DATA entries are read from the CRT display as they are changed.

PREVENTING DATA ENTRY

A function can be deactivated by pressing m . The active function readout is blanked and the ENABLED light goes out, indicating no DATA entry can be made. Pressing a function key re-enables the DATA controls.

DATA KNOB

The DATA knob 0 11a ows the continuous change of center frequency, frequency span (or start/stop frequen­cies), reference level, marker positions, display line, and threshold. It can also change the function values which are only incremented.
Clockwise rotation of the DATA knob will increase the function value. For continuous changes, the knob’s sensitiv­ity is determined by the measurement range and the speed at which the knob is turned. For example, when the center frequency is activated, one quarter turn.
increases the value of the center frequency one horizontal division of span per
0

DATA STEP KEYS

The DATA STEP keys allow rapid increase @ or decrease
dependent either upon the analyzer’s measurements range, on a preset amount, fixed values, the next value in a sequence. Examples: Activate center frequency and frequency value by an amount equal to one division of the frequency span (one tenth of the frequency span). If the center frequency step size m has amount. If frequency span were activated, sequence. Activate resolution bandwidth
single step,
16 Manual Operation
hen
10)
and [&
preset,
would change the span to the next lower value in predetermined
~
will select the next widest bandwidth.
--I
2)
of the active function value. The step size is
r
or,
for those parameters with
will increase the center
6
0
will increase the center frequency by that preset
El
Each press results in a
DATA DATA NUMBER/UNITS KEYBOARD

DATA NUMBER/UNITS KEYBOARD

The DATA number/units keyboard (or DATA keyboard) allows exact value entries to center frequency, frequency span (or start/stop frequency), reference level, log scale, marker positions, display line, threshold, and the COUP­LED FUNCTIONS.
An activated parameter is changed by entering the number (with the CRT display providing a readout) then selecting the appropriate units key. The value is not changed (entered) until the units key is pressed.
l
.
The number portion of the entry may include a decimal, number. Corrections to number entries are made with
Example: With center frequency activated,
(TJ-Jp-JJQ[Z][Z]~@
0
0
:::,:
If not, the decimal is understood at the end of the
,
which erases the last digit for each press.
will set the center frequency to 1.250
If the units key were pressed without a number entry, 1 is entered (except in zero frequency span).

Negative DATA Entry

Negative entries from the number units keyboard can be made for power and frequency but not time and voltage.
Negative power entries can be made using -Z . The “ - dBm” key will enter - dBm, - dBmV or - dBpV For example, in reference level, with the dBmV units, an entry of
Negative frequency entries can be made using
as a prefix to the frequency entry For example, to enter a negative start frequency, press
p-J(TJ(TJ@~
Not all functions will accept negative entries (the sign will be ignored).
This enters the frequency value as - 100 MHz.
GHz.
““I
0
will enter - 50 dBmV
m-m
z; (g-m
0

MULTIPLE DATA CHANGES

A function, once activated, may be changed as often as necessary without reactivating that function (see Chapter 3, FUNCTION). Any of the DATA controls can be used in any order. l
It is not always necessary to make a DATA entry. For example, start and stop frequency may be activated simply to allow readout of the left and right display reference frequencies as start/stop frequencies.
l Exceptions are the SHIFT KEY FUNCTIONS which use only DATA number/units keyboard. See Chapter 11.
Manual Operation 17
FUNCTION GENERAL DESCRIPTION
CHAPTER 3
FUNCTION

GENERAL DESCRIPTION

This chapter describes the use of the major function block- CENTER FREQUENCY FREQUENCY SPAN (or START/STOP FREQUENCY), and REFERENCE LEVEL.
NCTION -
A FUNCTION is enabled by pressing the desired FUNCTION key Once enabled, the function, along with its current data value, is displayed in the active graticule area of the CRT as well as outside the graticule border. To change the value of the active function, use either the DATA knob, step keys, numeric keyboard, or a combination of all three. The HOLD key above the DATA knob can be used to retain the present instrument state and prevent any inadvertent entry of DATA. HOLD clears the active function area of the CRT as well as de-activates any
function.
Active
Function
Frequency
Span
Manual Operation
19

CENTER FREQUENCY

CENTER FREQUENCY
FUNCTION
The center frequency can be tuned continuously from 0 to 22 Additional band overlap enables the center frequency to tune up to 24 GHz and below to - 1
The center frequency can be set with 1 Hz resolution. Readout resolution is 1% of the frequency span, hence the highest readout resolution is obtained with narrow frequency spans. Data entered, however, is always accurate to
1 Hz even though the center frequency readout may display less resolution.
During band crossings (from 0 - 2.5 or above 22 Appendix for detailed information.)

DATA Entry with CENTER FREQUENCY

[-iEz]
GHz),
(EC)
. . . .
#I
the frequency span may change to enable the desired center frequency to be set. (See
@@
GHz
low band to 2 - 22
Changes the center frequency by about one half the total frequency span each full turn.
Changes the center frequency by one tenth of the frequency span, i.e., by one division. COUPLED FUNCTION size.
Allows direct center frequency entry. The analyzer will accept a center fre­quency entry with 1 Hz resolution. Even though the readout may show a fewer number of digits (due to wide frequency span), as the span is nar­rowed the full entry will be read out. Abbreviated readouts are not rounded.
GHz
using any combination of DATA controls.
GHz.
GHz
microwave band) or at band edges (below 0 Hz
[‘::::‘I
can be used to change this step

Example

Once a signal response is placed at the center of the display, the frequency of the signal can be read out from CENTER FREQUENCY The input signal is a 9 GHz synthesized source.
Press
1’6::)
for a full span display.
20 Manual Operation
Tune signal to center of display with
. . .
L
b -
I. *
.-I.*
! ! ! ! ! 1
(-ZZ)~.
FUNCTION
Reducing the frequency span will increase the center
frequency readout resolution.
Press
then
[Fj
(x]
@
@

FREQUENCY SPAN

FREQUENCY SPAN
The frequency span changes the total display frequency range symmetrically about the center frequency. Note that the frequency span readout refers to the total display frequency range; to determine frequency span per division,
divide by 10.
As the frequency span is changed, resolution bandwidth and video bandwidth automatically change to provide a predetermined level of resolution and noise averaging, respectively. Sweep time also changes automatically to maintain a calibrated display.
The analyzer can be adjusted to span a maximum of 2.5 GHz in the low band and 22 GHz (2 to 24 the microwave band. A minimum span of 100 Hz is allowed in both bands as well as 0 Hz (zero span) which enables the analyzer to function as a fixed-tune receiver. In zero span, the analyzer can display modulation waveforms in the time domain.

DATA Entry with FREQUENCY SPAN

Changes the frequency span continuously.
GHz
range) in
Changes the frequency span to the next value in a 1,
2,5,
10 sequence.
Enters an exact value up to three digits, depending on span. Additional
digits will be deleted without rounding.
Manual Operation 21
I
FUNCTION
FREQUENCY SPAN

Example

Operating the spectrum analyzer in zero span. The modulation waveform of an AM signal can be displayed in the time domain.
In the frequency domain, we can accurately deter­mine the modulation frequency and level.
I
I
I
I I I I
I.1
I” I
To demodulate the AM, increase the resolution band-
width to include both sidebands with the IF passband.
L-E-@@
Position the signal at the reference level and select a linear voltage display
(G&ii)gFJ
fi
SCALE.
Manual Operation
23
START/STOP FREQUENCY FUNCTION
I/h
iii
To select zero span, press Video trigger can be used to trigger on the waveform. The sweep time control can be adjusted to change the horizontal scale.
[F)
m
a

START/STOP FREQUENCY

Another way to adjust the frequency range is by using START/STOP FREQUENCY instead of CENTER FRE­QUENCY and FREQUENCY SPAN. Activating START FREQ or STOP FREQ causes both to read out in place of CENTER FREQUENCY and SPAN on the CRT START FREQ sets the left graticule frequency and STOP FREQ
sets the right graticule frequency; both are mutually exclusive with CENTER FREQUENCY and FREQUENCY SPAN.
The INSTRUMENT STATE keys, w and m , select a start/stop frequency from 0 to 2.5 GHz and 2 to 22
GHz,
respectively. Additional over-range allows start frequency setting of - 1
The maximum start/stop frequency span allowable is 22
(START FREQ = STOP FREQ) .
GHz;
the minimum span is 100 Hz and zero span
GHz
and stop frequency of 24
GHz.
Start/Stop frequency readout resolution is 1% of the span (span = stop frequency - start frequency). Both start or stop frequencies can be entered with 1 Hz resolution.

DATA Entry with START/STOP Frequency

Changes the start or stop frequency. The amount of change per turn is a
constant percentage of the frequency span.
or
Changes the frequency by one tenth of the total frequency span.
Exact start or stop frequencies can be entered. The number of digits read out
depends upon the frequency span.
24 Manual Operation
REFERENCE LEVEL

DATA Entry with REFERENCE LEVEL

In logarithmic scale, the changes are in 0.1 dB steps: in linear scale, the changes are made to the least significant digit.
FUNCTION
pi?-)
pJ@
In logarithmic scale, changes the reference level in steps according to
division scale. In linear scale, changes the reference level in 1 dB steps.
Allows entry of exact reference levels. Digits entered beyond the displayed number of digits are deleted.

Example

Measure amplitude of calibration signal.
Press
@
(-E]
100 MHz
dB/
[ “%?)
To measure signal amplitude, press
and
position signal peak to top graticule line. Read ampli­tude from REF LEVEL.
26 Manual Operation
; ,
i
i
i
\
FUNCTION

FUNCTION/DATA SUMMARY

FUNCTION/DATA SUMMARY
CENTER
FREQUENCY
KNOB
Change continuously with up to 1 Hz
reso-
lution in narrow
0
STEP KEYS
spans.
Change frequency in one division steps
(i.e., 10% of fre- 5, 10 sequence.
@I@
NUMERIC
KEYBOARD Enter exact fre-
: t:: 1:::
rDJUSTMENT
RANGE
quency span).
quency with up to 1 Hz resolution.
-
1.000000000
:03.999999950
GHz
GHz. a
FREQUENCY
SPAN
m _
1 to
2.5 GHz
2 to 24
GHz
START/STOP
FREQUENCY
Change continuously
a
with n x 2 Hz resolu-
tion
*
- Change span in ” 2’
Enter
*
quency with n x 2 Hz
exact
fre- level. Digits entered
resolution *
m
100 Hz to 22 GHz and zero span.
106::
100 Hz to 2.5 GHz and zero span.
REFERENCE
LEVEL
Continuous with 0.1
dB tuning resolution.
Incremental change
in accordance with
log scale. In linear, changes incremen­tally in 1 dB steps.
Enter exact reference
beyond last displayed digit are deleted.
-
139.9
dBm
to
+60dBm.
READOUT
tESOLUTlON span),
* where n = harmomc number
1% of SPAN (Up to 1 Hz in narrow
0.1 dB in log; 4
c
nificant digits in lin-
ear.
sig-
Manual Operation 27
CRT DISPLAY OVERVIEW

Active Function

The function which has been activated for DATA entry is read out in the graticule area shown.
OFF 8 0 d&l .TTEN 18 dtl
I
!O do,
CRT DISPLAY
START
*.a c+I*
PFCI
BY 3
*Hz
Activating a function immediately writes its name in the active function area along with its present value. The
following summarizes the names and readout formats for the front panel designated active functions after an
INSTRUMENT PRESET
Function
FuNcT’oNc)
(,,,::c’)
COUPLED FUNCTION
I::‘1
pg)
Examples of Active
Function Readout
SPAN
20 GHz START
2
GHz
STOP
22 GHz
REF LEVEL
.O
dBm
RES BW
3 MHz
VIDEO BW
3 MHz
SWEEPTIME
500 msec
vB*
3
WI
r-
5TB Z2.B M,
5111’ 5RB “...<
Function
I--)
(,,,.
(,.J(I*I(1lM
REFERENCE LINE
(,.,,,
Examples of Active
Function Readout
MARKER
-
MARKER
12.0 GHz
19.8 dBm
MARKER A
20.0 MHz
-
12.4 dB
MARKER ZOOM
12.0 GHz
-
32.8 dBm
MARKER
12.0 GHz
140.4 dBm (1 Hz)
DISPLAY LINE
-
45.0 dBm
THRESHOLD
-
90.0 dBm
eactivates the active function and
bk$!s the
30 Manual Operation
active readout.
RF ATTEN
10
dB
CF STEP
100 MHz
SCALE
El
KEY FUNCTION
(See
[,,,I
KEY FUNCTIONS,
Chapter 11.)
LOG
10
dB/
CRT DISPLAY OVERVIEW
CRT DISPLAY
Display Unit
One display unit is the distance between two points (see above) along an X or Y
axis. The distance along the X axis between the far left graticule line and the far right graticule line is
1000 display units. The Y axis length between the bottom graticule line and the top graticule line is also 1000 display units. Although the Y axis can be extended another 22 display units above the top graticule line, the extended area is not calibrated.
X, Y coordinates to a particular point on the display are given in display units relative to X, Y
coordinates
Element
0,O
at the junction of the far left and bottom graticule lines.
An element is a distinct portion of the trace drawn on the CRT It comprises a point and the visible straight line drawn to it from the preceding point. An element drawn parallel with a vertical or horizontal graticule line is one diplay unit long. An element drawn at an angle to the graticule lines is longer, its actual length depending on the angle.
Vector
A vector is identical with an
Point of x, y coordinates
Overrange = 22 point
element,
A
I
.r
x
m
a.
except that it can be either visible or blanked.
Point of
x, y coordinates
su
t
-cr
R_
1000.1000
Manual Operation
32
Point of x, y coordinates
0.0
f
TRACE DISPLAY TERMS
Graticule center x, y coordinates 500,500
Point of x, y coordinates
1000,0
NOTE
When the analyzer is operated manually (i.e., with its front-panel controls), the display size remains constant and the above definitions are fully applicable. When it is operated remotely with a controller, however, three additional larger display sizes are available through the display-size programming commands. For these larger-than-normal dis­play sizes the lower left reference coordinates and the upper right trace limit expand beyond the CRT’s outer graticule lines. For further information on remotely-controlled
(i.e., programmed) display sizes, refer to commands
Dl,
D2, and D3 under Program-
ming Commands in Section II of this manual.
CRT DISPLAY OVERVIEW

Other Readouts

CRT DISPLAY
Title (see
Detection
Mode\,‘,’ deI
Amplitudeoffset
s”l”
KEY
(see
FUNCTION)
Display line
Threshold
\-=’
.-2L; ~
level
KEY
FUNCTION)
\
AEc....b<...,23.
REF .?3.8 dam
SAMYE
de
*a-
(see
Frequency offset
5~:;
KEY FUNCTION)
-
Marker amplitude and
frequency
(s_ee
MARKER)
Amplitude and/or
frequency
uncalibrated
A number of other special function readouts can be activated. These are covered in Chapter 11.
scales
34 Manual Operation
TRACE

TRACE IDENTIFICATION

CHAPTER 5
TRACE

GENERAL DESCRIPTION

This chapter describes the use of the TRACE functions for writing, storing, and manipulating trace data.
G--
‘P
TRACE Controls
TRACE
‘Trace
B
Trace A
Trace C
TRACE IDENTIFICATION
Traces are differentiated by intensity. Trace A is bright, trace B and trace C are dim. i and m allow positive identification.
Manual Operation 35
TRACE

TRACE EXCHANGE

To display the drift of a signal, press a
(Simulate frequency drift with
(ZEC)
0.1
&
hp
1e .”
liF .e &
ATlD4 10 Y
PI L !
Trace B sweeping Trace A
/
i
TRACE EXCHANGE
m
exchanges trace A and B, changing their relative intensities and storage memory locations and enables A
and B
[,..
. For example, in the trace display above, the modes and display appear.
4
1.
.
Trace
B
Clear Write
Trace A
Max Hold
Press
@
Manual Operation
39
TRACE
The display line is activated and set below the source/ analyzer response.
DL[tlgll a.
The difference between the display line (in display
units) and the source/analyzer response is stored in
trace B with I’;:’
TRACE ARITHMETIC
Negative values of the
[‘;:II
line are stored even
though not displayed.
Now the device under test is connected between source and analyzer and its response is corrected for source flatness uncertainty by using
BA@.
1”“““’
sr- ..Y -
rnmllwo
w-s-
-
7.Y n
- 2e.. -me.
Manual Operation 41
1

TRACE PRIORITY

TRACE
TRACE PRIORITY
Functions which act upon a trace always act upon the highest priority trace. Priority is defined by the trace modes as follows:
Highest priority
EB
view C
[,,..,]A
a
Lowest priority
Marker functions, for example, use trace priority to decide which trace to mark. See Chapter 6.
[.,,.,)B
blank C
42 Manual Operation
MARKER
DIFFERENTIAL MARKERS-A

Example

Set up m on the peaks of a fundamental (left) and its harmonic (right).
With the display referenced and scaled as shown, the readout
content. Percent is calculated as 100 x
“.0100X”
designates the fractional harmonic
(.OlOO)
= 1 .O%.
With a linear amplitude scale and a reference level calibrated in voltage, the fractional amplitude readout
is the simple linear ratio of the two markers.
Example
To measure % AM modulation from a spectra1 display, calibrate the display with the reference level in voltage and the amplitude scale in voltage.
Place the single marker on the carrier peak,
, and the second marker on one of the side-
0
band peaks, m 0 The fractional amplitude readout gives one half the modulation index .283.
%AM =
100x2x
.28 = 56%.
[--J
L INSR
. ..-.--

Measurement and Readout Range

The m function formats the amplitude readout according to reference level units and scale.
Reference
Level Units Logarithmic
SCALE
SCALE
Linear
dBm
dBmV
Amplitude in
dB
Amplitude in dB
dBpV
I
t
Voltage
Amplitude ratio
dB d,lferencr
-(
20 )
10
AMPLITUDE READOUT FORMAT FOR MARKER
Ratio of marker amplitudes
a
Manual Operation 47
DIFFERENTIAL MARKERS-A
MARKER
The frequency readout for all MARKER of span measured.
The amplitude readout in dB has a resolution of f
depends upon the LOG m value:

DATA Entry

The minimum incremental change for m frequency is 0.1% of the frequency span.
E--JO
m
conditions has up to 4 significant digits, depending upon the portion
.Ol
dB for linear scale. The resolution for logarithmic scale
LOG SCALE
dB PER DIV
One full turn moves the active marker about one tenth of the horizontal span.
RESOLUTION
EI@@
One step moves the marker one tenth of the horizontal span.
Positive entry places marker higher in frequency than the stationary marker, negative entry places marker lower in frequency. Larger entries than allowa­ble will place the marker on the adjacent graticule border,
Negative frequencies can be entered using a i m prefix as the minus sign. For example, to set a m span of 10 MHz with the second marker positioned to the left of the first, press

MARKER ZOOM

@
activates a single marker on the trace of highest priority (see TRACE
In
Ilo0.J
, the DATA knob and STEP keys change the values of different functions.
Positions Marker
0
PRIORIn
-
Chapter 5).
48 Manual Operation
Changes FREQUENCY SPAN and sets CENTER FREQUENCY equal to MARKER frequency
MARKER
DIFFERENTIAL MARKERS-A
DATA Control Use for
[,,,.
The marker can be moved along the trace with the DATA knob 0 , about the marker with DATA step @ and @ .
Each step also sets center frequency equal to the marker
frequency.
and the frequency span can be changed

Measurement and Readout Range

The measurement and readout range for marker zoom is the same as marker

DATA Entry

Moves the marker continuously along the trace. Rate dependent on speed of rotation. The marker moves in display unit increments.
Changes the frequency span to the next value in the sequence and sets the
El @J(g)
@a
center frequency equal to the marker frequency.
Places the marker at the frequency entered. An out-of-range entry places
the marker at a graticule border.

Example

(UL)
.
In wide frequency spans, it is often necessary to expand a portion of the frequency span about a specific signal in order to resolve modulation sidebands or track frequency drift.
Manual Operation 49

PEAK SEARCH

MARKER
Place a marker on the carrier with B
Press @FJ (,,:,,,I
.
Enter the span.
F’;;ls
m @ B , and auto zoom will be
0
-Aid
1 I 1 A 1 I I
200 kt-42
/I
I I I
i
I

PEAK SEARCH

Peak Search
Peak search places a single marker at the highest trace position of the highest priority trace. The active function is not changed.

Example

Use PEAR SEARCH to position the marker at the peak of the signal response.
In a narrow span, the marker may be placed at the signal peak.
Press m .
52 Manual Operation
MARKER ENTRY
A marker entry can be made any time a marker is on the trace. ( @ “r;;? with only one marker displayed takes 0 Hz as the lower frequency.) The active function will not be changed.

Example

MARKER
One of the fastest, most convenient ways to bring a signal to the center of the display is by using
Activate a
nal:
Change the center frequency to the marker frequency.
l”c:-]
will also work if start/stop frequencies are read out.
(,,,I 0
single
marker and tune it to the desired
.
sis-
l”r:-)
Example
One way to tune to a particular portion of a spectrum
being displayed is to use the A + span function.
Activate the single marker and place it at either end of the desired frequency span with
54 Manual ODeration
I--] 0
.
I
i
i i i
i
i i i
I
i
MARKER

PRESELECTOR PEAK

The upper carrier sideband is tracked with m then zoomed in with
[T]
Q m (%1.
As the carrier frequency is changed, the sideband response will tend to remain in the center of the display. The center frequency and marker frequency reads out the sideband’s frequency.
A combination of
(::GKw:l
and a allows the “real time” signal frequency drift to be read on the display.
PRESELECTOR PEAK
Preselector peak automatically adjusts the preselector tracking to peak the signal at the active marker. When the
marker is tuned to a signal and m is pressed, an internal routine searches for the peak response of the preselector and adjusts the tracking accordingly. Using preselector peak prior to measuring a signal yields the most accurate amplitude reading.
Preselector peak operates with the peak search routine and then peak the response at that marker. A “PEAKING!” message appears on the active graticule area to indicate operation of the peaking routine. PRESELECTOR PEAK only operates in the 2 - 22
GHz
preselected band.

Example

Peak the signal for accurate amplitude measurement.
Tune marker to signal of interest.
Press @ 0 .
I--]
,
(,,,.
, or m markers. If the marker is OFF pressing m will initiate a
Manual Operation
57
NOISE
LEVEL MEASUREMENT
Press m to peak preselector tracking. Measure amplitude by reading marker.
MARKER
The specific preselector correction factor applied in the example above is stored. A
[15::)
INSTRUMENT PRESET will not erase the correction factor; however, another PEAKING routine in the same band will store a new correction factor in that band.
The factory set preselector tracking can be recalled with by pressing
(,,, / (“:::1
(See Chapter 11.)
[,,,
= @ The preselector can be manually adjusted

How It Works

The internal preselector peaking routine automatically searches and sets the peak response of the YIG filter at the marker frequency. Each peaking operation only affects the frequency band in which the signal is located (four possible bands). A correction factor, representing the tracking offset, is stored in memory for that particular band each time the peaking routine is used. Correction factors (one per band) remain in memory unless a new peaking routine is initiated that may result in a different number. The last m correction factors are saved along with control settings in the internal storage registers upon execution of a
I-11
followed by a number from 1 to 6. Thus,
up to six correction factors could be saved for any of the frequency ranges listed in the chart below:
(
BAND 1 FREQUENCY RANGE
1
1
2
3
4
2.0 - 5.8
5.8 - 12.5
12.5 - 18.6
18.6 - 22
GHz
GHz
GHz
GHz

NOISE LEVEL MEASUREMENT

When noise level is activated and the marker is placed in the noise, the rms noise level is read out normalized to a
1 Hz noise power bandwidth.
58 Manual Operation
NOISE LEVEL MEASUREMENT
MARKER
Read the noise at the marker by pressing
The noise at 64 MHz is - 134 dBm in a 1 Hz bandwidth. This corresponds to - 134 dBm + 36
-
98 dBm in 4
kHz
voice channel bandwidth.
OBrl) b
dB/4
kHz =
Signal to noise measurements require the measurement of the noise level, as the example above, and the mea­surement of the absolute signal level.
Measure the power level of the turn the noise level off, press
fxiFJm
adp
*
signal. To
and read the
power level.
The signal to noise ratio referenced to 4
kHz
bandwidth is - 32 dBm - ( - 98
dBm)
= 66 dB.
*Normalization to a desired bandwidth uses the equation 10 log,0
60 Manual Operation
desired BW
(
1Hz
)
SCALE AND REFERENCE LINE

SCALE

Chapter 7
SCALE AND
REFERENCE LINE

GENERAL DESCRIPTION

This chapter describes the use of SCALE and REFERENCE LINE control groups for setting the amplitude scale, and for making amplitude level measurements more conveniently.
REFERENCE LINE
DISPLAY LINE
1:
THRESHOLD
E
SCALE
SCALE keys allow the scaling of the vertical graticule divisions in logarithmic or linear units without changing the
reference level value.
LOG.
m
(DATA entry) scales the amplitude to 1 dB, 2 dB, 5 dB, or 10 dB per division.
If m is pressed when the scale is linear, 10 dB per division will be automatically entered. The subsequent
(DATA), if any, will then replace the automatic 10 dB/div.
Press
Manual Operation 61
SCALE
AND
REFERENCE
LINE
Modulated AM signal displayed in the 10 dB/division scale shows the carrier, its sidebands, and distortion products.
Linear scaling enables the observation of the sidebands proportional to the carrier.
LIN
Press
(-J
SCALE
As in the MARKER m example, Chapter 6, a direct readout of the percent modulation can be
made.
The fractional readout is one -half the modulation index (only one sideband is measured).
%AM = 2(.25) x 100 = 50%.
Note that the carrier signal need not be placed at the reference level for an index ratio measurement.
LOG Change to a logarithmic scale with m and change the dB/division with @ @ .
The sidebands are 12 dB down from the carrier, veri­fying the earlier measurement results.
t
I
I
I
I III I
I
I
1
Manual Operation 63
REFERENCE LINE SCALE AND REFERENCE LINE
Harmonic distortion of the modulating signal can be
measured as in MARKER m , Chapter 6.
The modulation frequency is 18.8
kHz
and the distor­tion caused by the second harmonic is 2.4% (read out as .024X).

REFERENCE LINE

The reference line functions, DISPLAY LINE (DL) and THRESHOLD (TH), place horizontal reference lines on the display. Their levels are read out in absolute amplitude units.

DISPLAY LINE uses

l
measure signal levels with direct readout.
l
establish a standard for go/no-go test comparisons. eliminate or reduce amplitude errors due to system frequency response uncertainty
0

THRESHOLD provides:

a base line clipper whose level is read out.
l
a minimum threshold level that can be set.
0

DISPLAY LINE

DISPLAY LINE amplitude, in reference level units, is read out on the left-hand side of the CRT display.
64 Manual Operation
[1.1113
(DATA entry) places a horizontal reference line at any level on the graticule. The line’s
SCALE AND REFERENCE LINE
DISPLAY LINE
The DISPLAY LINE can be positioned anywhere within the graticule. When activated after LINE power ON or
m
, the display line is placed 4.5 divisions down from the reference level.
DISPLAY LINE display line is activated again before LINE power ON or
DISPLAY LINE position is always accessible for HP-IB and TRACE m ,
m
erases the line and readout from the CRT display but does not reset the last position. If the
[a;l:l
, it will return to its last position.
even if never activated. See Chapter 5,
TRACE ARITHMETIC.
The DISPLAY LINE readout has the same number of significant digits as reference level.

DATA Entry

t
(go
m @@
@iiJH
I
Moves the line about one division for each full turn. The line moves in display unit increments.
Moves the line one-tenth of the total amplitude scale per step.
Positions the line to the exact entry level. Entry may be in
+
dBmV,
or f
dB&
depending upon which units are selected.
mV, FV -I-
1
dBm,

Example

When the amplitude of a number of signals in the same span require a quick readout, the DISPLAY LINE can be used.
Activate the DISPLAY LINE with
With
0
0
, place the line through the peak of a signal
and read out its absolute amplitude level.
@
a
-94.9
d%“V
Moving the DISPLAY LINE to each signal reads out its amplitude.
Manual Operation 65

DATA ENTRY FOR COUPLED FUNCTIONS

COUPLED FUNCTION
Coupled
Function
i::‘1
ml
(::::‘I
[,1,,1
I’::::‘]
3 dB resolution bandwidth (IF filter) which largely determines the ability of the analyzer to
resolve signals close together in frequency. 3 dB bandwidth of the post detection low pass filter that averages noise appearing on the
trace. The total time for the analyzer to sweep through the displayed frequency span or display a
detected signal in zero frequency span. The setting of the input RF attenuator which controls signal level at the input mixer. Selects center frequency change for each DATA @
Selects
@
when
I=]
is activated.
DATA ENTRY FOR COUPLED FUNCTIONS
and
(.,,,.
Discrete values are entered for selects these values sequentially from the current value. A DATA entry from the keyboard which is not exactly equal to an allowable value will select an adjacent value. For example, bandwidth, the next higher IF bandwidth.
[:;‘I
,
[‘:“;“J
,
[‘I:::‘1
,
. The DATA entry from DATA
[::‘1
QQ@
and @j
a
will select 30
;,&J
kHz

RESOLUTION BANDWIDTH

[:;‘I
(DATA entry) sets bandwidth selection to MANUAL and changes the analyzer’s IF bandwidth. The band-
30
widths that can be selected are
1 MHz, and 3 MHz.

Example

10 Hz,30Hz,
100 Hz,
Hz,1kHz, 3 kHz, 10 kHz,
300
kHz, 100
kHz,
300
kHz,
A measurement requiring manual resolution bandwidth selection is the zero span (time domain) observation of modulation waveforms. An example can be found in Chapter 3, ZERO FREQUENCY SPAN - FIXED TUNED RECEIVER OPERATION.
70 Manual Operation
COUPLED FUNCTION
Another use of manual resolution bandwidth is for better sensitivity over a given frequency span.
The low level intermodulation products of a signal needs to be measured. With the functions coupled, the analyzer noise may mask the distortion products.
Reduction of the noise level by 10 dB (increased sensi­tivity) is achieved by decreasing the bandwidth by a factor of 10.
--

VIDEO BANDWIDTH

(THRESHOLD has been activated to clarify the dis-
play.
1
lu
4l.B
k
The sweep time automatically slows to maintain absolute amplitude calibration if m is coupled.
VIDEO BANDWIDTH
[.;“.“)
(DATA entry) sets the video bandwidth selection to manual and changes the analyzer’s post detection filter bandwidth. The bandwidths
kHz,
30
kHz,
100
kHz,
that can be selected are 1
300
kHz,
1 MHz, and 3 MHz.
hp
19
.
Hz,
3
Hz, 10 Hz,30Hz,
100 Hz,
300 Hz, 1
kHz,
3
kHz,
10
Manual Operation
7 1
VIDEO BANDWIDTH
COUPLED FUNCTION

Example

Signal responses near the noise level of the analyzer will be visually masked by the noise. The video filter can be
narrowed to smooth this noise.
A low level signal at this center frequency can just be discerned from the noise.
Narrowing the video bandwidth clarifies the signal and allows its amplitude measurement.
Press m @I @I @l
@I
The sweep time will increase to maintain amplitude calibration.
NOTE
The video bandwidth must be set wider or equal to the resolution bandwidth when measuring pulsed RF or impulse noise levels.

Video Averaging

Narrowing the video filter requires a slower sweep time to keep amplitude calibration, since the narrower filter must have sufficient time to respond to each signal response. Video averaging is an internal routine which
djgjtalfy
averages a number of sweeps, allowing a more instantaneous display of spectra1 changes due to center frequency,
frequency span, or reference level changes. See Chapter 11.
72 Manual Operation
COUPLED FUNCTION INPUT

Zero Attenuation

As a precaution to protect the spectrum analyzer’s input mixer, 0 dB RF attenuation can only be selected from the
number/units keyboard, press
Reference Levels I - 100 dBm and > + 30 dBm
Reference levels 5 - 100 dBm or between + 30 dBm and + 60 dBm can be called when the reference level extended range is activated. Low reference level limits depend upon resolution bandwidth and scale.
I
Press
m (,1,.1
to extend the reference level range.
(,,,.1
@(x-
Al7ENUATlON
See Chapter 3, FUNCTION

Determining Distortion Products

If the total power to the analyzer is overloading the input mixer, distortion products of the input signals can be displayed as real signals. The RF attenuator can be used to determine which signals, if any, are internally generated distortion products.

Example

The two main signals shown are producing intermod- ulation products because the analyzer’s input mixer is overloaded.
(F)
,
and Chapter 11,
(,.,,,
KEY FUNCTIONS.
To determine whether these intermod products are generated by the analyzer, first save the spectrum dis­played in B with @I B B B.
t i
- ,lb..l. LWS
lis L 1 h”Z
i
i ii i
VI 100
“a
Manual Operation
i
i i 1
9*H 1” .)u
JIP 1... .
.
75

CENTER FREQUENCY STEP SIZE

Increase the RF attenuation by 10 (If the reference level changes, it will be necessary to
return it back to its original value.)
dB.
Press m
0
0
hp
1. .”
COUPLED FUNCTION
e -I..8 h
cwa-rm 1m.114 Y(*
- I I LCIX
Since some of the signal responses decrease as the attenuation increases (by comparing the response in A with the stored trace in B) , distortion products are caused by an overloaded input mixer. The high level signals causing the overload conditions must be attenuated to eliminate this condition.
1 I
1
YI 1.. “1
I
1
I
WIN 1” LHI
op 2.. ..*
1 ]
CENTER FREQUENCY STEP SIZE
m
(DATA entr ) sets step size to MANUAL, changes and stores the step size entered into a register. While
and
0
is in MANUAL, functions can be used to enter step size value to the register. When a CF STEP SIZE is AUTO, the center frequency steps will be 10% of the frequency span, even though the CF STEP SIZE register contains another value.
step size
SPAN or LINE power ON
I”::::il
&E-]
[,,,,
, [ FULL
(DATA entry)
change center frequency by the step size value stored in the register. Several
0
m
Entry Value
100 MHz
DATA entry value
uncoupled (MANUAL)
State
coupled (AUTO)
[“::::‘)
MARKER
The step size can be varied from 0 Hz to greater than 20 GHz with 1 Hz resolution. It is displayed with the same resolution as center frequency.
76 Manual Operation
@
marker frequency readout
uncoupled (MANUAL)

TRIGGER

SWEEP
AND
TRIGGER
The SWEEP light indicates that a sweep is in progress. The light is out between sweeps and during data entry. (The
light is out for sweep times
110
msec.)
After a sweep, the next sweep will be initiated only if:
continuous sweep mode is selected or a single sweep demand is made,
0
the trigger conditions are met,
0
l data is not entered continuously from the front panel DATA controls or the HP-IB.

Continuous Sweep

[-1
enables the continuous sweep mode. Provided the trigger and data entry conditions are met, one sweep will
follow another as soon as triggered. Pressing m initiates a new sweep.

Single Sweep

@
enables the single sweep mode. Each time
[,,,,,,I
is pressed, including when the SWEEP mode is changed
from continuous, one sweep is initiated provided that the trigger and data entry conditions are met. A sweep in
progress will be terminated and restarted upon (,,.,,, .

Zero Frequency Span Sweep

In zero frequency span, sweep times from 1 psec to 10 msec are also available. In these sweep times, the SWEEP
[,,,)
, @ are disabled. The video signal response is not digitally stored (trace modes also disabled), but multi­plexed directly onto the display along with the graticule and readouts. The graticule and readouts are refreshed following each fast sweep.
To avoid flicker of the display when external or video triggers are less frequent than 25 msec, the analyzer will
trigger internally. If triggers dependent only on external or video trigger are required, press
or
[,nl) ‘(d’
11.111) ‘[,,,,
b]
isa
es “auto” external trigger feature
disables “auto” video trigger feature
For zero frequency span sweep times
NOTE
110
msec and
11*111)
x or @ y, the CRT display graticule and readout depend upon triggering. If no trigger is present, the CRT display will be blank.
TRIGGER
The analyzer sweep is triggered by one of four modes selected.
l
(:2:.,
allows the next sweep to start as soon as possible after the last sweep.
l
i
allows the next sweep to start when the line voltage passes through zero, going positive.
l
[
allows the next sweep to start when an external voltage level passes through =
The external trigger signal level must be between OV and +
80 Manual Operation
5V
1.5V,
going positive.
SWEEP AND TRIGGER
l
B
allows the next sweep to start if the detected RF envelope voltage rises to a level set by the LEVEL
EXTERNAL TRIGGER INPUT
TRIGGER
knob. The LEVEL corresponds to detected levels displayed on the CRT between the bottom graticule (full CCW) and the top graticule (full CW).
An RF envelope will trigger the sweep only if it is capable of being traced on the CRT display-that is, the resolution bandwidth and video bandwidth are wide enough to pass the modulation waveform of an input signal.

Example

A zero span display of this video waveform will trigger for all LEVEL knob settings.
If the video signal lowers on the display, the LEVEL must be set towards the minus side.
t
i
I
I
1
If the level does not cause a trigger within 25 msec, the sweep will be triggered anyway to ensure a display. Note that this is true only for sweep times
~10
msec.
Manual Operation 81
INSTRUMENT STATE

LOCAL OPERATION

LOCAL OPERATION
@
enables front panel control after an HP-IB remote LISTEN or TALK command has been executed. An HP-IB local lockout will disable
STANDBY
then ON again.
@
until an HP-IB return to local command is executed or the LINE power is turned to
Indicates instrument has been addressed through
HP-
IB.
Indicates instrument is in remote operation.
The addressed light remains on until an HP-IB device clear command or any unlisten command is executed.
Manual Operation 87
(,,,rr
KEY FUNCTIONS

GENERAL DESCRIPTION

Chapter 11
I
KEY
FUNCTIONS
GENERAL DESCRIPTION
This chapter describes access and use of the B KEY FUNCTION.
Shift functions supplement a front panel function or provide unique measurement capabilities. The @ functions are not named on the front panel but are coded by the blue characters beside the keys.
frequency offset function is designated by the code V On the front panel the code V is found in the FUNCTION
section :
V
For-
example, the
The shift functions are activated by pressing complete summary of shift FUNCTIONS is in this chapter under FUNCTION SUMMARY There is an index to all shift functions at the end of this chapter.

Example

Activate the shift function V (frequency offset) with
press
press
The shift light can always be turned off with
m

DATA Entry

An active shift function value is read out and identified in the active function area of the display the same as any other function using DATA entry Once the data has been entered, any other function can be activated. The shift function will retain its last value until the a key is pressed, or the LINE switch is switched to STANDBY
[
does not disable the selected shift function (except for title).
shift light on
shift light off and offset function activated
(WTII
and then the front panel key with the appropriate blue code. A
I--u]
,
which returns the front panel keys to their designated function.
Manual Operation 89

FUNCTION SUMMARY

FUNCTION SUMMARY
k&
KEY FUNCTIONS
General
r HP-IB Service request
P Enter HP-IB address
f
Power on in last state
z
Display Address
j
Display Write
Amplitude
Z Amplitude offset
A Units: dBm
B C
dBmV dB@
D voltage
I Extended reference level
range
-
Negative entry
, Mixer level
Marker
K
Marker to next peak N Marker to minimum 0 Enter A+ span M Noise level on
L Noise level off u
Stop single sweep at marker = Factory preselector setting
/
Manual preselector setting
Display
o Annotation blanked p Annotation on
w Display correction data
g CRT beam off h CRT beam on
m Graticule blanked
n Graticule on
E
Title
Trace
c
A+B-+A
Detection:
normal
Fl
positive peak
d negative peak
e
sampling
Trace C:
k
blank trace C
i
B?t,C
1
B-C view trace C
j
G Video averaging on H Video averaging off
Trigger-Zero Span
x
1
without 25 msec triggering
y
B
without 25 msec triggering
Instrument State
( Save registers locked
) Save registers unlocked
T
Fast preset 2 - 22
U
Fast preset external mixer
GHz
S Fast HP-IB operation
t Band lock
Q Band unlock
Error Correction
W Execute routine
X Use correction data Y
Do not use correction data
w Display correction data
Diagnostics
w Display correction data
q Disable step gain R Frequency diagnostic on F YTO pretest mode
J Manual DACS control
#
Turns off YTX self-heating
correction
Frequency
V Frequency offset
-
Negative entry
v
Signal identifier ext. mixer

ALPHABETICAL KEY CODE SUMMARY

*A Amplitude in dBm
B Amplitude in dBmV C Amplitude in dBpV D Amplitude in voltage
E
Title
F Removes IF Offset for YTO
preset
G Video averaging on
l
H
Video averaging off
I Extended reference level
range
J Manual DACS control
K
Marker to next peak
l
L
Noise level off M Noise level on N Marker to minimum 0 Enter A + span
P Set HP-IB address
*
Q Band unlock
R Frequency diagnostic on S Fast HP-IB operation
T
Fast preset 2 - 22 GHz
U
Fast preset external mixer
V Frequency offset
*n
*p
W Execute error correction
routine
X Use correction data
*Y
Do not use correction data
Z Amplitude offset
*a Normal detection
b Positive peak detection c
A+B-‘A
d Negative peak detection e Sample detection
f
Power on in last state g CRT beam off
*h
CRT beam on
i
BsC
j View trace C
*k
Blank trace C
I
B-C
m Graticule blanked
‘These functions selected with [‘a.‘:l INSTRUMENT PRESET
Graticule on
o Annotation blanked
Annotation on
q Disable step gain
r HP-IB service request
t Band lock
u
Stop single sweep at marker
v
Signal identifier ext. mixer
w Display correction data
111
without 25 msec triggering
X
y
ll=o
without 25 msec triggering
El
z
Display address
-
Negative entry
= Factory preselector setting
/
Manual preselector setting
( Save registers locked
) Save registers, unlocked
I Display write
Mixer level
i
Turns off YTX self-heating
correction
I
90 Manual Operation
151111
KEY FUNCTIONS
DATA entries to shift functions are made only from the number/units keyboard. The ENABLED light remains off even though data may be entered.
Data is entered (that is, changes the instrument state) only when a units key is pressed. If the entry has no units (an address, for example), use the0p!!.
key as the terminator.
(,.,,, -,v,z

NEGATIVE DATA KEYBOARD ENTRY

Entering negative data from the DATA keyboard requires the use of a negative symbol prefix on the number entry.
Negative entry:
For example, to enter a negative 100 MHz offset frequency:
Press &
Press (,..I] (-I
Not all values can be entered with a negative prefix. For example, a negative entry to a voltage reference level will
result in entering the positive value.
Negative entries in dB can be made with the - dBm units key or the negative prefix with the + dBm units key. If both negative prefix and
[,.,,, (
[z)
to activate frequency offset.
0
-7;:
0
m
m @
are used, the value will be entered as positive.
to enter a negative frequency.

FREQUENCY AND AMPLITUDE OFFSET

The CRT display amplitude and frequency readout can be offset. Entering an offset does not affect the trace.
V
Frequency offset:
Amplitude offset:
Offset entries are added to all the frequency or amplitude readouts on the CRT display, including marker, display line, threshold, start frequency, and stop frequency.

FUNCTION

To eliminate an offset, activate the offset and enter zero. A FULL SPAN key also sets the offsets to zero.
Offsets are stored with the
(,,,,I [=I
[,,,
functions for recall with
(DATA keyboard entry)
(DATA keyboard entry
@
.
Manual Operation 91
When an offset is entered, its value is displayed on the CRT
iji
ii
i”“;?
KEY FUNCTIONS
I
i
I
i i
DATA entry from the keyboard can be in Hz, amplitude. The amplitude offset readout is always in dB. An entry in voltage can be made and will be converted to
dB
offset.
The offset range for frequency is - 99.999999990 to + 99.999999999 GHz in 1 Hz steps. The amplitude offset range is greater than f 100 dB in 0.1 dB steps. Least significant digits will be truncated for frequency and
amplitude offset entries.

Example

An 102.6 MHz up converter with 12.7 dB attenuation is placed between a signal source and the spectrum analyzer. The offsets can be set so that the CRT display shows the trace referenced to the signal as input to the converter.
Amplitude offset is entered as a positive value to com-
pensate (offset) the loss of the converter.
kHz,
MHz, or GHz for frequency and dB, - dB, mV and FV for
Note that the original REF LEVEL of 0 dBm is now changed to 12.7 dBm also.
92 Manual Operation
m
KEY FUNCTIONS
(,.,,, V -,
A, B, C, D
Frequency offset is entered as a negative value since the input frequency to the converter is lower than the output.

EFFECTIVE MIXER LEVEL

The effective mixer level is equal to the REFERENCE LEVEL minus the INPUT ATTENUATOR setting. It speci­fies the maximum signal level that will be applied to the input mixer for a signal that is equal to or below the REFERENCE LEVEL. A FULL SPAN key (0 - 2.5 GHz or 2 - 22 is 5 dB below the analyzer’s 1 dB compression point. The effective mixer level can be manually set from - 10
dBm * to - 70 dBm in 10 dB steps by pressing [ , (comma sign) and entering the desired
numeric keyboard. For instance, to set a mixer level at -40 dBm, press: (,,IIl , analyzer’s REFERENCE LEVEL is changed, the coupled input attenuator will automatically change to limit the maximum signal at the mixer to - 40 dBm for signals I REFERENCE LEVEL.
GHz)
sets the mixer level to - 10 dBm, which
eve1
through the
m d
(zl
. As the

AMPLITUDE UNITS

The following shift key codes immediately select the corresponding units for all the amplitude readouts: reference level, marker, display line, and threshold.
When a units change is made, all readouts are converted so as to preserve the absolute power levels of all the readouts. For example, a 0 dBm threshold level converts to 47.0 dBmV (50 ohm input) when dBmV units are called.
SHIFT KEY
FUNCTION
i
A. . . . . .
@
B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
[,,,,,
C . . . . . . . . . . . . . . . . . . . . . . . . . . . . dBpV
m
D . . . . . . . . . . . . . . . . . . . . . . . . . volts
(or FULLSPAN key) . . . . . . . dBm
The keys for these functions are located in the COUPLED FUNCTION group.
AMPLITUDE
UNITS
dBmV
‘In the Extended Reference Level Range (Shift I, under EXTEND REFERENCE LEVEL RANGE in this chapter), the effective mixer
level can be set to 0 dBm.
Manual Operation
93
H I, =,/
k&
KEY FUNCTIONS

EXTEND REFERENCE LEVEL RANGE

Normally, the reference level can be set from - 89.9 dBm to + 30.0 dBm in coupled operation. The limits of the range can be extended to a maximum of - 139.9 dBm and + 60 dBm.
I
press B
The lower limit of reference level depends upon resolution bandwidth and scale.
Scale
m
Resolution Bandwidth
Minimum reference level
with extended reference level
10 dB attenuation
0 dB attenuation
h
lo9
linear linear
11 kHz 23 kHz sl kHz >3kHz
-
129.9 dBm
-
109.9 dBm
-
109.9 dBm
-
89.9 dBm
-
139.9 dBm
-
119.9 dBm
-
119.9 dBm
-
99.9 dBm
When the reference level is set at a minimum, the level may change if either scale or resolution bandwidth is changed. The extended range is disabled with instrument preset.

FACTORY PRESELECTOR SETTING

Activating provides a preset adjustment for each of the four frequency bands in the 2 - 22 GHz range. These preset adjust-
ments optimize the preselector tracking over the full 2 - 22 GHz frequency range. The tracking can be optimized at any single frequency with the the other three bands. (See Chapter 6 for more information.)
(,,t
= will reset the internal preselector to a factory set 2 - 22 GHz tracking range. The factory setting
()::::LJ
key. A @ adjustment in one band will not affect the preselector tracking in

MANUAL PRESELECTOR TRACKING

The internal preselector can be manually adjusted for a peak response in the 2-22 GHz band. m /
enables manual entry of a DAC number from 0 - 63 with the DATA knob, step keys, or numeric keyboard. The DAC reading corresponds to a voltage which sets a particular preselector tracking offset. The location of the MARKER determines the band (four independently adjustable bands) to be adjusted.
The Manual Preselector Tracking function is useful for peaking the preselector at locations where a stable CW signal is absent. For instance, drifting signals or pulse modulated signals do not easily lend themselves to the use of
@
. The automatic preselector peak routine depends on a stable CW signal. In this situation, a means for
manually tracking the preselector may provide a more reliable setting.
94 Manual Operation
@
(,,,,1
i, I, B, j,
m
KEY FUNCTIONS
The sweep will be suspended, the trace in memory B will be read and written into trace C from left to right in about 20 msec. Trace C is viewed. Sweeping will then resume from where suspended. The trace information in B is not changed.
To exchange traces B and C
The trace information in B and C is interchanged point for point from left to right in about 20 msec. If trace B is not displayed, it remains undisplayed. If trace C is not displayed, it remains undisplayed.
To store TRACE A into trace C. the trace A data must first be transferred into trace B:
press
or press m
m
(I*(rl
1 (which also erases last trace
(,.,,,1
i (which also saves last trace C in
C)
B)

Example

Comparisons of up to three different signal traces can be made simultaneously using traces A, B, and C. In this example, the modulation level of a signal will be changed for each trace. To start, clear the display with and
[,,,.,
B.
(,,,,
A
The signal with the desired level of modulation will be stored in trace C:
Press
m
B and allow one sweep.
Press
(,,,,
1 which writes the trace from B into C.
Change the modulation level, allow one sweep and store in B with m B.
To view C, press m j.
100 Manual Operation
a
KEY FUNCTIONS
m
A, ‘2, H
Change the modulation level again and press m A, and store with
(,,,.
A. The three traces are differenti-
.
ated by intensity.

VIDEO AVERAGING

Video averaging is a trace display routine that averages trace responses from sweep to sweep without requiring a narrow video bandwidth. (Averaging with the video bandwidth is discussed in Chapter 8, COUPLED FUNCTION
m .)
Both video averaging and reducing video bandwidth are primarily used to improve the analyzer’s ability to
measure low-level signals by smoothing the noise response.
To activate video averaging (and sample detection mode),
G
press
(z] [??I
(DATA keyboard entry)
H
To disable video averaging, press
(,, @
CAUTION
Video averaging may result in an uncalibrated amplitude display when
frequency span
Resolution Bandwidth
Readout in the active function display area is “VID AVG
> 1000
100”.
The number represents the maximum number of samples (or sweeps) for complete averaging. The DATA entry can be used to change the maximum sample number in integers from 0 to 1000. A unity sample limit allows direct writing of analyzer response into Trace C (see Trace C below). A 100 sample limit is selected upon instrument preset. The higher the sample limit, the more smoothing possible. Averaging with high sample limits can provide more smoothing than the 1 Hz video band­width.
During video averaging, the current sample being taken is read out at the left of the display.
Manual Operation 101
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