HP 86908 User manual

HEWLETT. PACKARD
Multi-band capability provides un-
precedented versatility
Interchangeable RF Units give you
multi-band capability at low cost
Dials are easy to change, keyed
1OM 1169/7.5M0370
Printed In U.S.A.
CONVERTIBLE
SWEEP
OSCILLATORS
model
86908
8691-8697
8706A, 8707A
86988,86998
TECHNICAL DATA 1 MAR 70

Page 2
Introduction
The Hewlett-Packard 8690B Sweep Oscillator forms the
basis of many types
of swept-frequency systems. The 8690B
Sweep Oscillator accepts nine RF units capable of cover-
ing the frequency range from 0.4 MHz to 40 GHz. An
8690B/RF Unit may be used alone or with a wide variety
of accessory equipment. For example, multi-band sequen-
tially swept coverage is provided by employing the HP
8706A Control Unit and up to three 8707A RF Unit Hold-
ers, permitting the 8690B Mainframe to drive as many as
eight RF unit sweep oscillators.
86908 Sweep Oscillator
The Hewlett-Packard 8690B Sweep Oscillator combines
interchangeable RF units with high accuracy, versatility, and
ease of operation to bring you all the advantages of single
unit sweep oscillators plus economical multi-band capability.
With no adjustments required, the changing of RF units
is quick and easy and the snap-in dial is keyed for accurate
positioning. The front panel has a logical, straightforward
layout for ease of operation. The frequency dial is the full
width of the instrument for maximum resolution.
Careful design of all-new solid-state power supplies re-
sults in exceptionally low residual FM, and provides rugged
protection against system transients.
INC. FM = 750kHz
j_
250
kHz
T
Fi9ure 1. Low incidental FM of square-wave modulated
8693B is shown in this oscillogram. Measurement made
with HP 2590B Microwave Frequency Converter.
RF Units
The HP 8698B (400 kHz -110 MHz) and 8699B (1 oo
MHz - 4 GHz) Solid-State RF Units provide four decades
of frequency coverage with only two plug-ins.
By use of
heterodyne techniques, careful filtering, and advanced mi-
crocircuit technology, broadband coverage is achieved along
with superior performance.
Microwave RF units employ high reliability Backward
Wave Oscillator tubes
(BWO) which carry an uncondi-
tional one-year warranty.
Two types
of microwave RF units are available, permit-
ting selection to meet any application requirement. HP
PIN diode modulation and leveling are available in the
Model8690B
"B" type RF units from 1 to 12.4 GHz. The 8691-4B RF
Units offer exceptional frequency accuracy (between 0.5%
and 1%) over a wide range of modulation conditions. HP
PIN diode RF units are the only RF units that specify full
power frequency accuracy over a 10-dB dynamic range,
considerably enhancing measurement accuracy. All modula-
tion functions including leveling are performed independent
of the backward-wave oscillator tube (BWO). The result
is the virtual elimination of frequency pulling during either
modulation or leveling, which, in turn, results in extremely
high frequency accuracy and linearity and very low inci-
dental FM. Figure 1 illustrates the low incidental FM
associated with square-wave AM.
The "A" series of RF units employs conventional BWO
grid modulation for AM functions. This series covers the
entire 1-40 GHz spectrum in seven models (8691A-8697A)
and is used in the bands above 12.4 GHz, where PIN attenu-
ators are not available, and in lower bands when modulation
requirements are less demanding.
Sweep Functions and Markers
The 8690B Sweep Oscillators provide a broadband "start-
stop" sweep whose end points can be set anywhere in the
band. Independent controls set the start and stop frequencies
on the slide-rule scale. Thus the units can sweep up or down,
depending only on the setting of the start frequency with
respect to the stop frequency. There
is no interaction be-
tween the start and stop control settings. Selecting the start-
stop sweep is simply a matter of pushing a button.
Two independent frequency markers, set separately on
the dial and direct-reading in GHz, can be positioned
any-
where in the band. The markers amplitude-modulate the
RF output, providing triangular markers. These markers
have points sharp enough to give high resolution on narrow
sweeps, yet are broad enough to be quite visible on even the
broadest sweeps. Figure 2A shows that the markers are
plainly visible on a full-band sweep. In addition, marker
amplitude can be adjusted from the front panel. Adding
the markers to the display is again a matter of pushing
buttons.
The markers can also be used as end points for a second
broadband sweep which starts at the Marker 1 frequency
and ends at the Marker 2 frequency. Thus, the 8690B
Sweep Oscillators have two independently adjustable broad-
band sweeps, providing a high degree of flexibility. For
example, should the start-stop sweep reveal a particular area
of interest, the markers can be adjusted to bracket the area;
then a simple depression of the Marker Sweep button ex-
pands the bracketed area to cover the full horizontal scale
of the indicating device-oscilloscope or X-Y recorder.
Figure 2B illustrates this display expansion. The marker
sweep need not be within the start-stop sweep. Thus the
start-stop sweep can be set to cover one range, such as the
passband
of a filter, and the marker sweep can be set to
cover another range, such
as the stop band.
Besides sweeping from a start frequency to a stop fre-
quency, the 8690's provide a calibrated narrow-band sweep
which is symmetrical about a center frequency. Simply
press the .!lF button, set the center frequency with the Start-
CW control, and adjust the deviation with the Stop-LlF
control. Total swing is indicated on the bottom slide-rule
)
)

Model8690B
A
B
Figure 2. (A) Full-band start-stop sweep with markers. (B)
Expansion of 2A display between markers on Marker Sweep.
scale. The frequency markers can be applied to the llF
sweep as well as the start-stop sweep.
As noted above, the Start-CW and Stop-llF controls are
used for the llF sweep. Thus the marker controls can be
used for wideband sweep applications and the start-stop
controls for
llF operation. This provides independently
adjustable wide and narrow band sweep modes with full cali-
bration for both modes.
Sweep Modes
Recurrent, triggered, and manual sweeps are available.
Recurrent and triggered sweep times are adjustable from
0.01 to 100 seconds, and the triggered sweeps can be syn-
chronized from an external source or manually (front-
panel pushbutton) for photography or X-Y recording. To
enhance the clarity of oscilloscope presentations, RF power
is blanked during retrace to produce a zero baseline; how-
ever, RF is restored before the start of the subsequent sweep
to eliminate transients during the early part of the sweep.
Blanking can be disabled, when desired, with a rear-panel
switch. Oscilloscope photography of slow sweeps is simpli-
fied by a front-panel sweep indicator. This indicator turns
on automatically at the start of the sweep and turns off at
the end. Thus there is no guesswork about when to close
the shutter and remove the film and no time wasted waiting
to be sure the sweep is finished.
For X-Y recorder presentation, an automatic pen-lift
circuit
is provided. The circuit drops the pen during the
stabilizing period prior to the sweep and lifts the pen dur-
ing the second stabilizing period which occurs at the end of
Page 3
the sweep just before retrace. Thus transients and retrace
lines are eliminated from X-Y plots.
On manual sweep, a front-panel control varies the RF
frequency between the limits set on the selected sweep func-
tion. With the use of the manual sweep, X-Y recorder setup
time
is reduced to seconds.
The sweepers provide their own voltage ramp concur-
rently with the RF sweep for driving the horizontal systems
of oscilloscopes and X-Y recorders. While this ramp varies
somewhat from unit to unit, it remains the same within a
given unit regardless
of sweep mode, duration, or direction.
Once the sweep end points have been set on the recording
device, they will remain the same for any sweep. Thus the
broad flexibility and simple push-button operation of these
units can be fully utilized.
In addition to the sweep voltage from the sweep oscil-
lator, the RF units provide a reference voltage which is
proportional to the output frequency. This reference is
about zero at the lowest frequency and increases about 40
volts per octave. The reference, available at the rear of the
RF units, can be used to drive an external monitor when a
continuous indication of frequency
is required. It is also
especially useful with the new
HP 8410A Network Analyzer
system to enable accurate phase-lock synchronization at high
sweep speeds.
Leveling
The 8690B Sweep Oscillators are designed for external,
closed-loop leveling. This technique minimizes the varia-
tions in output amplitude with frequency which are inherent
in backward-wave oscillators. A basic leveling setup is
shown in Figure 3. The leveling signal, the result of RF
sampling
by the directional coupler and detection by a
crystal detector,
is applied to a leveling amplifier built into
the sweep oscillator. The amplified signal is applied to the
PIN diode attenuator in the "B" series of RF units and to
the
BWO grid in the· "A" series to maintain a constant
power at the output of the directional coupler. External
leveling therefore eliminates the frequency-dependent trans-
mission characteristics of any components (cables, connec-
tors, amplifiers, filters, etc.) between the oscillator and
sampling point.
External leveling with directional couplers has the further
advantage of virtually eliminating source mismatch. Thus
leveled power can be established at any point in a system,
even though it is remote from the source. The degree of
leveling
is determined primarily by the characteristics of the
directional coupler and detector.
86908
w
DETECTOR
Figure 3. Basic leveling configuration in coax.

Page 4
86908 OSCILLOSCOPE
SWEEP
·~c
~
®HO~IZ
V~T
(,)
l I
SWEEP
J I
L DETECTORS
r-v '-1i --~
1.:::: =TEST DEVICE
DUAL ' 0
DIRECTIONAL ' SHORT
COUPLER
Figure 4. Coaxial reflectometer.
Internal leveling
is available as Option 001 on most RF
units operating below 12.4 GHz. The directional coupler
and detector
of Figure 3 are located within the RF unit and
the output
of the coupler becomes the output of the sweep
oscillator. Internally leveled units are useful in less critical
applications
in which transmission variations between os-
cillator and test point are not significant or a package free
of external elements is desired.
Modulation
All modulation functions are selected by pushbutton and
can be used simultaneously. Included
is internal square-
wave modulation, with a range
of 950 to 1050 Hz, plus
external
AM and FM. The external AM input is de-coupled
to permit de control
of amplitude and can be utilized even
during leveled operation.
The external FM input is also de-
coupled to permit external frequency programming, and
the response to a full-band step change
is typically less than
2 milliseconds. The frequency response to sinusoidal
FM
is 150 Hz for full-band swing. Maximum swing decreases
to about
1% of the band at 20 kHz. Greater-than-specified
deviations at modulating signals above 150
Hz can be ob-
tained at a sacrifice
in linearity.
Swept Systems Applications
The range of application for swept-frequency techniques
covers all microwave measurement areas: impedance, attenu-
-hp- 1416A
-hp- 141 A Swept Frequency
Oscilloscope Indicator
0
-hp-86908
Sweep
Oscillator
Device
under test
~~~t~~~~~.~
-hp- 817A
-hp- 907A
Sliding Load
Figure 5. The 817A Swept Slotted Line system provides
inexpensive and precise SWR measurement from 1.8 to 18
GHz.
Model8690B
ation, power, frequency, etc. The most widely used swept-
frequency system has been the reflectometer, which,
in
measuring return loss and SWR, provides impedance infor-
mation. Figure 4 illustrates the basic reflectometer setup in
coax; the waveguide setup
is similar. Above 4 GHz, the low
directivity
of coaxial directional couplers has been a serious
limitation
in the coaxial reflectometer. Hewlett-Packard,
therefore, recently developed the Model 817A Swept Slot-
ted Line system capable of measuring very low standing-
wave ratios with a high degree
of accuracy from 1.8 to 18
GHz. The design simplicity
of the 817A Swept Slotted
Line system shown in Figure 5 provides broadband, pre-
cision, coaxial SWR measurements at roughly a third
of the
cost
of previously available hardware.
Frequency response, whether
in the form of attenuation
in a passive device or gain
in an active device, is another
parameter readily measured on a swept-frequency basis. A
typical measurement setup in waveguide
is shown in Fig-
ure
6.
The new Hewlett-Packard Model 8410A Network Ana-
lyzer provides one simple system capable
of measuring both
amplitude and phase
of all network parameters from 110
MHz to 12.4 GHz. The 8410A Network Analyzer is shown
in Figure
7, with the HP 8690B Sweep Oscillator measuring
both the amplitude and phase transmission characteristics
of
a YIG filter. The 8410A is capable of measuring phase,
gain, loss, impedance, admittance, reflection coefficient, and
angle. Phase and amplitude output data may be obtained
either from a linear meter readout or in polar form with the
HP 8414A Polar Display.
The
HP sweeper has been designed to be especially com-
patible with the advanced 8410A Network Analyzer system.
The 8690B supplies a sweep reference voltage output
which
is used to synchronize the 8410A sampling phase-
lock oscillator permitting phase-lock operation at the fastest
sweep speeds, providing a flicker-free oscilloscope readout.
The 8690B Oscillator has been designed to provide a de-
layed sweep start-up, enabling the 8410A Network Analyzer
system to phase-lock before the initiation
of the sweep. This
delayed sweep start-up capability
is also especially useful
86908 OSCILLOSCOPE
»m "' [;J I \:ili:L, ~"'
t---~1 SWEEP r
t-l :J]_DETECTOR
i ·~~1::'·-x}""u~,"
i COUPLER
I
I TEST
I !. T DEVICE
I r-x-- ~
'-1 10/20D8 1------p.--.--~
DIRECTIONAL DETECTOR
COUPLER
Figure 6. Frequency response setup.

Model8690B
Figure 7. HP 8410A Network Analyzer (110 MHz to 12.4
GHz) shown measuring phase and amplitude response of
YIG filter.
in driving X-Y recorders, permitting recorder stabilization
before the initiation
of the sweep· ramp. The B Model
8691 through 4 plug-ins incorporates the unique
HP PIN
diode leveling capability, providing greater dynamic range.
Page 5
This enables
an operator to reduce swept output signal to
a level that will not overdrive the 8410A Network Analyzer
system.
8706A Control Un RF Unit Holder
The Hewlett-Packard 8706A Control Unit and 8707A RF
Unit Holder provide you with an inexpensive solution to the
need for broadband sweep capability.
The Model 8706A
Control Unit substitutes for the normal RF unit in the
8690B Mainframe and
is capable of programming up to
three 8707A RF Unit Holders, providing up to eight bands
of frequency coverage from one HP 8690B Mainframe. The
HP 8706A/8707A is described on page 10.
Applications Literature
HP Application Note 65, titled "Swept-Frequency Tech-
niques," provides
an up-to-date discussion and error analysis
of the most frequently used swept-frequency setups and
measurements techniques. Copies
of Application Note 65
are available at all Hewlett-Packard field offices.

Page 6
Mode!s 8691 8691 RF U
(Installed in 86908 Sweep Oscillator)
Frequency Range
Frequency Accuracy
(at max. leveled power)
Maximum leveled Power
RF Power Control
< Frequency Stability
With Temperature
[: With 1 O% Change in Line Voltage
With Power level Change
Residual FM (CW mode)***
['. Power Variation, External leveling**
f:•. Output Impedance and/or Connector
·I·· Pri~e
:· 1.· Option 01. Internal Leveling
8691A
1 to 2 GHz
±1%
At least 100 mW
BWOGrid
± 0.01%/"C
±500kHz
Typically < 20 MHz
(for 6 dB)'
<30kHz peak
± 0.2 dB
50 ohms/Type N
$2,025.00
86918
1 to 2 GHz
± 10MHz
At least 70 mW
PIN Line
±
0.01%/oC
±500kHz
±500kHz
(for 10 dB)
<10kHz peak
± 0.1 dB
50 ohms/Type N
$2,375.00
Model8690B
Power Variation
Equivalent Source Match
Price
± 0.4 dB
1.13:1
Add $315.00
1
Down from max. leveled power.
Models 86928
100 RF
(Installed in 86908 Sweep Oscillator}
Frequency Range
Frequency Accuracy
(at max. leveled power)
Maximum leveled Power
~F Power Control
Frequency Stability
With Temperature
With 10% Change in Line Voltage
With Power level Change
Residual FM (CW mode)***
Po~er Variation, External leveling**
Output Impedance and/or Connector
Price
8692A
2 to 4 GHz
±1%
At least 70 mW
BWOGrid
± 0.01%/"C
±500kHz
Typically< 40 MHz
(for 6 dB)'
<30kHz peak
± 0.2 dB
50 ohms/Type N
$1,825.00
8692B
2 to 4 GHz
± 20 MHz
At least 40 mW
PIN Line
±
O.Ol%/°C
±500kHz
±4MHz
(for 10 dB)
<15kHz peak
± 0.1 dB
50 ohms/Type N
$2,175.00
8692B Opt. 100
1.7 to 4.2 GHz
± 25 MHz
At least 15 mW
PIN Line
±
0.01%/°C
±500kHz
±4MHz
(for 10 dB)
<20kHz peak
±
0.1 dB
50 ohms/Type N
$2,475.00
,
Option 01. Internal Leveling
Power Variation
Equivalent Source Match
Price
± 0.4 dB
1.16:1
Add $315.00 1
Down from max. leveled power.
Models 86938
100 RF
(Installed in 869013 Sweep Oscillator)
,', Frequency Range
Frequency Accuracy
(at max. leveled power)
Maximum Leveled Power
RF Power Control
Frequency Stability
With Temperature
With 10% Change in line Voltage
With Power level Change
Residual FM {CW mode)***
Power Variation, External leveling**
Output Impedance and/or Connector
ji .1'.-ice
I
,,
Option 01. Internal leveling
Power Variation (into matched load)
Equivalent Source Match (approx.)
Price
8693A
4 to 8 GHz
±1%
At least 30 mW
BWO Grid
±
O.Dl%/"C
± lMHz
Typically < SO MHz
(for 6 dB)'
<50 kHz peak
± 0.2 dB
50 ohms/Type N
$1,625.00
± 0.5 dB
1.25:1
Add $350.00
86938
4 to 8 GHz
± 40MHz
At least 15 mW
PIN Line
±
o.01%/°C
± lMHz
± 1MHz
(for 10 dB)
<15kHz peak
± 0.1 dB
50 ohms/Type N
$2,025.00
± 0.4 dB
1.25:I
Add $350.00
86938 Opt. 100
3.7 to 8.3 GHz
± 45MHz
At least 5 mW
PIN Line
± O.OI%fOC
± lMHz
± 1 MHz
(for10dB)
<20kHz peak
±
0.1 dB
50 ohms/Type N
$2,325.00
± 0.4 dB
1.25:1
Add $350.00
1 Down from max. leveled power.
*See page 8 for common specifications. **Excluding coupler and detector variation.

Model8690B Page 7
\)

Page 8 Model 8690B

Model8690B Page 9

Page 10 Model 8690B
DESCRIPTION
The first simple and relatively inexpensive solution to
the problem of broadband sweep capability (more than
an octave) is offered by Hewlett-Packard's Model 8706A
Control Unit with the Model 8707A RF Unit Holder.
When used with the HP Model 8690B Sweep Oscillator
and appropriate RF units, a compact, bench-top multi-
band source is formed.
The Model 8706A Control Unit with its nine band
selector buttons, replaces the usual RF unit as a plug-in
for the sweep oscillator mainframe. It supplies power
for and controls as many as three Model 8707A RF Unit
Holders, each of which accommodates three RF units.
Thus it is possible to obtain complete frequency cover-
age from 400
kHz to 40 GHz with one easy-to-use sys-
tem.
Units may be programmed either by front panel con-
trol unit pushbutton selection, or sequentially by re-
mote contact closure to ground. The 8706A also can
provide voltages for control of remote circuits, relays,
etc. By utilizing
these voltages to program a coaxial
switch,
for example, you can channel the output sig-
nals of several RF units through a single system output
connector. Multi-band tests can then be made quickly
and easily; changing RF unit3 and cable connections is
handled automatically at the touch of a button.
Switching time between bands is one second, with
no degradation of BWO life. This is an exclusive new
accomplishment. Two separate types of sweep capa-
bility are available
in each band. If normal sweep is
selected
for one or more of the RF units in the 8707A
RF Unit Holder, the
breadth of the RF unit sweep will
correspond to the setting of the start/stop cursor on
the sweeper mainframe-100% if 0 and 100 are select-
ed,
or any proportion as designated on the start/ stop
dial. A second preset mode is available for one or more
RF
units by pre-adjusting start/ stop frequency settings
made on potentiometers adjacent to each RF unit plug-
in in
the 8707A RF Unit Holder.
Unnecessary operation of BWO tubes should be
avoided to prolong their life. At the same time, it is de-
sirable to
have the output of any RF unit quickly avail-
able.
The 8707A sweep system maintains the BWO's
on standby, removing the high voltage when not in use
to extend tube life. When a single band is not to be
used over some period of time, for example during a
laboratory set-up procedure, an individual RF unit may
easily be turned off, minimizing all aging effects.

Model 8690B Page 11

Page 12
Model 8690B
Description
The Hewlett-Packard 8698B RF Unit for the HP 8690B
Sweep Oscillator covers a frequency range from 400 kHz
to 110 MHz
in two ranges. The all solid-state plug-in al-
lows swept measurements to be made easier and more
accurately for the following reasons:
Sweep linearity is ±0.5% of sweep width and frequency
accuracy of the start and stop points is nominally 1% of
frequency. With the plug-in's high linearity and frequency
accuracy, the operator can use the internal graticule
markings on his oscilloscope as a frequency scale and can
then accurately define the frequency response of ampli-
fiers, filters,
and other devices.
Maximum output is +13 dBm (20 milliwatts) into a 50-
ohm system. Output power is calibrated in 10 dB steps
from +13 to -110 dBm with vernier adjustment between
steps. Calibrated power makes it easier to define gain and
loss in networks and amplifiers.
A built-in leveling circuit holds
the output flat within
±0.3 dB throughout the maximum sweep width, providing
accuracy in measuring a device's amplitude response.
Residual FM is less than 300 Hz on the 0.4- 11 MHz
range
and less than 1 kHz on the 4- 110 MHz range, assur-
ing clean, stable displays when testing narrow band
devices.
Harmonics are at least 30 dB down and spurious re-
sponses 35 dB down over the entire frequency range.
There are many convenient sweep functions: START-
STOP, MARKER SWEEP,
and ~F. All sweeps are cali-
brated and accurate.
The 8698B can be voltage-programmed in both ampli-
tude and frequency and is capable of AM and FM.
Other significant features are a 0.4- 11 MHz auxiliary
output which allows the user to monitor frequency up to
110 MHz with an 11 MHz counter (such as the HP 5321),
a 5 MHz
crystal calibrator, an uncalibrated RF output, a
sweep reference output, and a 200.4- 310 MHz VTO
output.
The HP 8698B RF Unit is all solid-state throughout, in-
corporating thin-film microcircuit amplifiers in its design.
Power consumption is thus held low and reliability high.

Model 8690B Page 13
86988 Specifications
(Installed in 8690B Sweep Oscillator)
FREQUENCY CHARACTERISTICS
Range: Low range, 0.4 -11 MHz; high range, 4-110 MHz.
Accuracy: (CW, AF center frequency, end points of start-
stop and marker sweep; except when 8690B is in Ext
FM mode.)
Low Range: ±1% of frequency ±50 kHz.
High Range:
±1% of frequency ±500kHz.
Linearity: ±0.5% of sweep width.
Harmonics and Spurious Responses:
Non-Harmonics:
At least 35 dB below CW output.
Harmonics: (Output levels below +10 dBm) At least
30 dB below CW output.
Residual FM: (CW and Sweep)
Noise in a 10 kHz bandwidth including line related
components:
Less than 300 Hz rms, low range.
Less
than 1 kHz rms, high range.
Combined Incidental and Residual FM with internal
square wave modulation:
Less than 600 Hz rms, low range.
Less than 2 kHz rms, high range.
Residual AM: AM noise modulation
index (rms, 10 kHz
bandwidth) is less than -40 dB.
OUTPUT CHARACTERISTICS
Level: +13 to -110 dBm. Output is calibrated in 10 dB
steps and at +13 dBm. Uncalibrated vernier provides
continuous level settings over entire range.
Accuracy: ±1.5 dB at any calibrated level.
Flatness: ±0.3 dB over full range.
Impedance: 50 n, SWR <1.2 on 0 dBm step and below.
RF Leakage: Conducted and radiated leakage limits are
below those specified in MIL-I-6181D.
SWEEP CHARACTERISTICS
(Operating controls are located on the 8690B)
Start-Stop Sweep: Sweeps from "start" to "stop" dial
setting.
Marker Sweep:
Sweeps from "Marker 1" to "Marker 2"
dial setting.
In
both Start-Stop and Marker Sweep, dial settings are
continuously and independently adjustable over the en-
tire
frequency range and can be set to sweep either up
or down in frequency.
AF Sweep: Sweeps upward in frequency, centered on CW
dial setting.
AF Width Accuracy:
Low Range: ±3% of sweep width or ±20 kHz, which-
ever is greater.
High Range:
±3% of sweep width or 200 kHz, which-
ever is greater.
Sweep Speeds: Continuously adjustable in four decade
ranges 0.01 to 100 seconds/sweep, or with manual con-
trol from front panel, providing continuous tuning over
preset limits.
Sweep Modes: Automatic [free running), line synchro-
nized,
or triggered by either front panel pushbutton or
external pulse.
Sweep Indicator: Front panel indicator lights during sweep
duration.
MARKERS
(Controls on 8690B)
Two frequency markers, independently adjustable over
the entire frequency range, amplitude modulate the RF
output. Marker amplitude is adjustable from the front
panel.
Marker Accuracy:
Low Range: ±1% of frequency ±50 kHz.
High Range:
±1% of frequency ±500 kHz.
Resolution:
Low Range:
±5kHz.
High Range: ±50 kHz.
Marker Output: Triangular pulse, typically
-5 V peak
into 1 kO.
MODULATION
Internal AM: Square wave modulation continuously ad-
justable from 950 to 1050 Hz. On-off ratio (level vernier
in calibrated position) is 20 dB.
External AM:
Bandwidth: DC to 5kHz at 30% modulation.
Sensitivity: -10 V reduces RF output at least 20 dB
(level vernier in calibrated position).
IJ?.put Impedance: Approximately 1 kO.
External FM: (Sweep selector in "manual" position)
Bandwidth: Deviations to
the band edges are possible
for
rates to 100 Hz. Smaller deviations possible at
rates up to 10 kHz.
Sensitivity: Deviation from CW setting is approximately
6% of frequency band per volt.
CRYSTAL CALIBRATOR
Internal 5 MHz crystal allows frequency calibration to
±0.01% at any 5 MHz multiple using front panel fre-
quency vernier.
AUXILIARY OUTPUTS
(Rear Panel)
Sweep Reference Output: Provides voltage analog to fre-
quency output. Approximately 1 V /MHz on low range,
1 V /10 MHz on high range.
Uncalibrated RF Output: -5 dBm minimum.
VTO Output: -15 dBm minimum. 200.4- 310 MHz.
Auxiliary Output:
Always 0.4 -11 MHz, for low frequency
counter monitoring.
GENERAL
Power: Supplied by HP 8690B Sweep Oscillator.
Weight: Net,
11lb (5,0 kg). Shipping, 18 lb (8,2 kg).
Dimensions: 41/z in. wide, 71/4 in. high, 171/z in. deep
(115 mm x 185 mm x 445 mm).
Price: Model 8698B, $1,550.00.
Options:
001: 75 n output impedance (BNC), add $50.00.
004: Rear
panel RF output, add $75.00.

Page 14
e ULTRA-BROADBAND-5 OCTAVES
e ALL SOLID STATE
e LINEAR SWEEP
e PIN LEVELING/MODULATION
e LOW RESIDUAL FM
e LOW SPURIOUS CONTENT
e ECONOMICAL AND CONVENIENT
The Hewlett-Packard 8699B RF Unit is a completely
solid-state
0.1 to 4 GHz plug-in unit for the HP 8690B
Sweep Oscillator. It is extremely versatile and can be
used for a wide range of applications requiring an ac-
curate, stable, easy-to-use swept frequency source.
BROAD FREQUENCY COVERAGE: Five octaves of
frequency coverage, together with good stability and
low residual FM, make the 8699B useful for testing
both broadband and narrowband devices. With this
single RF unit,
fast and accurate swept measurements
can be made from VHF through S band, bringing con-
Model 8690B
venience and economy to lab and production test ap-
plications.
COMPLETELY SOLID-STATE: Outstanding per-
formance
and high reliability have been achieved
through state-of-the-art design and advanced hybrid
integrated circuit technology. The result is broad fre-
quency coverage
and high output power while fre-
quency stability
and low spurious output are main-
tained. This completely solid-state RF source elimi-
nates the expense of BWO replacement, resulting in
additional
operational economies.

Model 8690B Page 15
8699B DESCRIPTION
Broad frequency coverage on the 0.1 to 2 GHz band
is achieved with a heterodyne design. The output of a
YIG oscillator,
tuned from 2.3 to 4.2 GHz, is mixed with
a fixed 2.2 GHz signal. The 0.1 to 2 GHz difference fre-
quency is amplified by a broadband, thin film amplifier.
Undesired higher order signals are eliminated before
the amplifier by a low pass filter having a sharp cutoff
and low insertion loss at 2.0 GHz.
The thin film amplifier is the key element in the
heterodyne design. With over 40 dB gain, it can de-
liver high
power to the load while maintaining low
spurious
and harmonic content. Even at maximum lev-
eled power, spurious outputs are below the level
where
they would affect the accuracy of most measurements.
A PIN modulator is
used to control the output of the
2.2 GHz oscillator, thus providing external leveling ca-
pability
down to 100 MHz. By placing the PIN modu-
lator before
the mixer, spurious output is reduced
when less than maximum leveled power is required.
Frequency pulling
with level or load change is low
since the PIN modulator presents a constant load to the
2.2 GHz oscillator.
On the 2 to 4 GHz band the mixer and amplifier are
switched
out of the circuit and the YIG oscillator is
tuned from 2 to 4 GHz. The PIN modulator remains in
the circuit for leveling
and to provide AM modulation
capability. The inherent linearity of
the YIG oscillator
results in a very linear
swept output and leads to ac-
curate frequency displays on
both bands.

Page 16
Model 8690B
8699B SUPPLEMENTAL OPERATING
INFORMATION
REMOTE PROGRAMMING: For digital programming
of CW frequency, a special version of the 8690B Sweep
Oscillator is available (8690B Opt. H26) that incorpo-
rates a Digital-to-Analog converter and accepts 12-line
BCD input.
MULTIBAND OPERATION: When the 8699B is in-
stalled
in an RF Unit Holder (HP 8707 A) and the HP
8706A Control Unit is used, the frequency range of
operation must be selected manually with the switch
on the front panel of the 8699B. To switch ranges re-
motely,
use a modified Control Unit (8706A Opt. H25).
LEVELING: With a directional coupler and crystal
detector,
the power variations across the frequency
band of interest will depend primarily on the frequency
REAR PANEL CONNECTIONS
• EXT ALC GAIN:
Adjust ALC gain for optimum leveling across the band.
C) SWEEP REFERENCE OUTPUT:
Voltage
output proportional to RF frequency. Approxi-
mately 0 to +40 V output on 2 to 4 GHz range only
(compatible
with HP 8410A Network Analyzer). There
is no output on the 0.1 to 2 GHz range.
response of the coupler and detector used. An alterna-
tive scheme,
useful in the frequency range of the 8699B,
is to
use a power splitter instead of a coupler to sample
RF power. With this technique, the maximum leveled
power available at the output will be lower, but overall
flatness will be improved.
EXTERNAL FM:
Modulating signals may be applied
to either the front panel EXT FM input on the 8690B
Sweep Oscillator (with the SWEEP SELECTOR in
MANUAL) or to the rear panel PHASE LOCK input of
the 8699B. For best performance, the latter technique
should be used. The front panel EXT FM input should
be used mainly for remote frequency control or for
modulation at wide deviations and very low rates
(<1 kHz).
• REMOTE RANGE SELECT:
Permits remote range selection
by a contact closure to
ground. A 3-prong
phone plug inserted into this rear
panel input will disable the MANUAL range switch on
the front panel. For 0.1 to 2 GHz, the plug tip is
grounded; for 2 to 4 GHz, the tip is opened.
G PHASE LOCK INPUT:
Input terminal for phase-locking control voltage or ex-
ternal FM signal. For phase-locking, the input sensi-
tivity
of 1 MHz/volt is compatible with the HP 8709A
Synchronizer. For FM modulation, Figure 8 shows the
maximum deviation that typically results when the in-
put level is held constant and the modulation rate is
varied.
:!:30
N
J:
::2
z
0
[i
>
w
0
X
<!
::1:
::!:3
±I
1.0
MODULATION RATE (KHz)
Figure 8
For more information, call your local HP Sales Office or East {201) 265-5000 • Midwest [phone] • South [phone]
West [phone]. Or, write: Hewlett-Packard, 1501 Page Mill Road, Palo Alto, California 94304. In Europe, 1217 Meyrin-Geneva
5952-0936