Boonton 92A User manual

MODELS 92A/92AB
PROGRAMMABLE RF MiLLIVOLTMETER
92A/AB
b-1271

BOONTON ELECTRONICS CORPORATION
Route 287 at Smith Road
Parsippany, N. J ,
07054

ifcjooMTor^i
Rf MItLIVOLTMETER
9009 '^
MODEL JliiAfi
CHAR6E
MODEL 92AB
BATTERY OPERATED RF MiLLiVOLTMETER

CHAPTER
NTRODUCTION
IJ GENERAL
The Model 92 Series RF Millivoltmeter provides an accurate readout of measure¬
ments from the low radio frequencies to the gigahertz region, over a voltage range of
200 pV to 3 volts. It is a programmable, solid-state instrument of high sensitivity and
occuracy, characterized by high input impedance (see Figs. 1 and 2), excellent sta¬
bility, and low noise.
The Model 92 exhibits true rms response for input signals up to 30 millivolts,
gradually approaching peak-to-peak above this level. The meter, however, is cali¬
brated in rms above this region.
Input and output connections for externa! control and readout are provided by a
22-pin card-edge connector at the rear of the instrument.
A linear dc output, whose level is proportional to the rf input voltage, is also
provided at a rear connector. This may be used to drive a recorder, remote indicator,
or other analog devices.
The 92 offers a convenient and accurate means for making a wide variety of mea¬
surements. Typical uses of this instrument include:
In transistor testing the instrument may be used to measure p, f^., and other
transistor parameters.
VSWR and return loss measurement using the Model 92 Series with bridge
methods, directional couplers, and adjustable or slotted lines.
Gain and loss measurements in wide-bond amplifiers, including such de¬
sign characteristics as stage gain, flatness of the pass band, upper cut-off
or corner frequency, negative feedback factors, and other parameters.
Proper adjustment of tuned circuits in narrow-band amplifiers.
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The adjustment^ measurement of performance, and evaluation of rf filter
parameters.
Measurement of vswr or return loss and attenuation of rf attenuators.
Measurement of output levels of signal generators, adjustment of baluns,
harmonic distortion of rf signals, and adjustment of circuits for minimum
voltage (null) or maximum voltage (peak).
The Model 92 is available in several optional configurations with a basic accu¬
racy of 1% rdg. + 1% fs. The standard features of the instrument are:
Remote programmability
Measures from 200 pV to 3V* from 10 kHz to 1 .2 GHz.
True rms response to 30 mV**
Convenient push-button ranging.
DC analog output.
High input resistance, low input capacitance.
Overload protection to 400 Vdc to 10 Vac.
VSWR less than 1 =15 up to 1.2 GHz.
* To 300V, up to 700 MHz, with accessory 100:1 divider.
** To 3V, up to 700 MHz, with accessory 100:1 divider.
Thecharacteristicsof the instrument include: high reliability, fast warm-up (I min-
ute), long intervals between calibrations, plug-in PC boards for ease in servicing or
modifying, lightweight, and other advantages of sol id-stage design.
1 .2 EQUIPMENT DESCRIPTION
The Model 92 is basically a programmable analog instrument with linear dc out¬
put. It is available with a full range of options and accessories as described in Chap¬
ter II. Input range programming by external contact closure or PNP transistors to ground
is standard.
The instrument is sensitive, accurate, sturdily constructed, and protected against
overoads. It will perform overextended periods of time without failure or need for
recalibration. It is packaged as acompact oench instrument that can be easily mounted
in a standard 19-inch rack using an optional rack-mounting kit.
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Important Input and accuracy specifications ere reproduced on a reference piate
fastened to the exterior top cover of the instrument. Clips for holding out-of-use ac¬
cessories are provided at the rear of the instrument. Calibration instructions are re¬
produced on the underside of the top cover of the instrument.
Standard accessories supplied with the Model 92 Series include one each of the
toi lowing:
Model 91-12F RF Probe with low-noise cable and connector.
Model 91 -8B 50-ohm BNC adapter.
Model 91-13B Probe Tip (removeable) with grounding clip lead,
A complete kit of probe accessories is available as optional equipment. Including
a storage case with space for the Model 91-12F RF Probe and the other standard ac¬
cessories.
1,2.1 Frequency Capability
Thecalibrated frequency range of the Model 92 extends from 10 kHz to 1 2 GHz
with uncalibrated response to beyond 8 GHz. Relative accuracy above 1 2 GHz is
typically ±0.5 dB.
instnl^nTfor 50 ® ° standard accessory with the
I 3*2 t voltage measurements up to 600 MHz. A correction curve fFia-
'ociuded for frequencies above SOM^Hz. For higher-frequency measurtrnents
Adloter^ir^^" volfage measurements the optional accessor^ Model 9i-i4A Tee
Adapter, is recommended, ft is designed to comoensate for fhp rf
and to present o good vswr (better than 1 .15) upTo 2 u^^
junction with the Model 91 y 5A50-ohm load for terminated voltage Lesure^
1.2.2 Voltage Capability
The Model 92 has eight ranges, from 1 millivolt full scale to 3 volts full scale,
arranged in 1-3-10 sequence. No attenuator attachments are required for measure-
ments up to 3 volts. While this range Is ample for most rf voltage measurements, the
capability of the instrument can be increased to 300 volts (up to 700 MHz) by using
the optional accessory. Model 91-7C 100:1 Voltage Divider. Use of the 100:1 Volt¬
age Divider also increases the input resistance of the Model 91-4C RF Probe by a fac¬
tor greater than 100.
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1 o2„3 True RMS Response
The Model 92 provides true rms response for signal inputs below approximately
30 millivolts (below 3 volts, up to 700 MHz, with the Model 91-7C 100:1 Voltage
Divider). As the input level increases, the waveform response gradually approaches
peak-to-peak, calibrated on the Indicator in rms. Thus, in addition to making precise
sinusoidal voltage measurements at all levels, the instrument measures non-sinusoidal
or asymmetrical signals within the rms region without loss of accuracy.
1 .2.4 Low Noise
The Model 92 has been designed and constructed to hold noise from all sources
to a minimum.
The probe cable is of special low-noise design; a vigorous flexing causes only
momentary, minor deflections on the most sensitive range. The Model 91-12F Probe is
not sensitive to shock or vibration; even sharp tapping on the probe barrel causes no
visible deflection on any range.
Amplification takes place at 94 Hz, reducing susceptibility to any 50 or 60 Hz
line-frequency-related fields. A unique circuit reduces the low-level noise origin¬
ating from the mechanical chopper and renders the instrument immune to changes in
chopper performance that could occur with the passage of time.
1 .2.5 Minimal Zero Adjuslment
Zero adjustment Is not required on the upper five sensitivity ranges of the Model
92. For measurements on the lower three ranges, the ZERO control Is set on the most
sensitive range before operation. This control balances out small thermal voltages in
the probe elements and, once adjusted, requires only infrequent checking during the
course of subsequent measurements.
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1.2o6 DC Output
The 92 provides a linear dc output whose current capability of 1 mA into 1000
ohms is extremely stable^ When used as part of an automatic test system, the fast re¬
sponse of the instrument's dc output to an input step function allows more tests per unit
time.
For system or external requirements, all input and output connections for the 92
are made at the card-edge connector on the rear of the instrument. (See Figure 11
for receptacle connections.)

CHAPTER I
Voltage Range:
Full Scale
Voltage Range:
dBm Range;
Frequency Range:
Accuracy:
300 mV to 3V
2CK) pVto 300mV*
Meter:
Meter
Unrest;
(1 mV fs range
only)
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SPECIFICATIONS
200 |jV to 3V (300V up to 700 MHz with accessory 1 00:1 voltage
divider).. Voltage sensitivity is 100 pV.
1, 3, 10,30, 100, 300, 1000, and 3000 mV.
-60 to +23 dBm (463 dBm up to 700 MHz with optional accessory.
Model 91-7C 100:1 Voltage Divider).
10 kHz to 1 .2 GHz (uncalibrated response fo approximately 8 GHz),
1% fs plus
1% rdg
2% rdg
1% rdg
3% rdg
1 0% rdg
7% rdg
10 kHz 50 kHz 150 MHz 700 MHz 1 o2 GHz
*Below 1 mV, add 1% fs
4-1/2 inch taut-band
Two linear voltage scales
0 to 3; 0.05 per division
0 to 10; 0.1 per division
One logarithmic dBm scale
-10 to 43; 0.2 per division max.
Indicated Voltage
Unrest
Above 600 pV
300 pV to 600 pV
1 00 pV to 300 pV
< 1% fs
< 2% fs
< 5% fs

Power:
RFI:
Temperature:
Waveform
Response:
Crest Factor:
Input Impedance:
VSWR:
Power Sensitivity:
DC Output:
Dimensions:
92A: 115 or 230 V ±10%, 50 to 400 Hz.
92AB: 115 or 230 V ±10%, 50 to 400 Hz, and two 18-voit re
chargeable batteries
There is no detectable radiated or conducted leakage from instru¬
ment or probe.
In accordance with ANSI (ASA) Spec. 39.7
Temperature
Range
Temperature Influence
Instrument
RF Probe
Ref. 21° C to 25° C
Normal, 18° C to 30° C
Severe, 10° C to 40° C
0
0
±1% rdg
0
±1% rdg
±4% rdg
True rms response for input levels up to 30 mV (3V to 700 MHz
with 100:1 Voltage Divider), with transition to peak-to-peak (cali¬
brated in rms) at higher levels.
420 to 1 .4 depending upon input level (see Table 11).
See Figures 1 and 2o
Less than 1 ,15 to 1.2 GHz (Return Loss greater than 23 dB). See
Figures 3 and 4.
200 pW, minimum detectable power in 50 ohms.
0 to 10 Vdc proportional to rf input voltage* Source resistance of
9 kO; wi II deliver 1 mA into 1 kQ lood. Full scale Input step func¬
tion response time less than 100ms on 30mV fs to 3Vfs ranges, in¬
creasing to 1 sec. on the 1 mV fs range.
5.2" H (without rubber feet), 8.3"W (1/2 of standard 19 inch rack
module) 11.5" D (132 x 211 x 292 mm).
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Weight:
Accessories
Furnished:
Warm-Up:
Accessory Kit
(Optional)
Model 91-24A:
Other
Accessories
(Optional)
Available:
92A: Net 7 lbs, (3.2 kg)
92AB: Net 10 lbs. (4.54 kg)
Model 91 -1 2F, RF Probe„ RF Probe with low-noise cable and con¬
nector assembly for measurements from 10 kHz to lo2 GHz; see
Figures 1 and 2 for input resistance and capacitance.
Model 91-13B, Probe Tip. Removable Probe Tip with grounding
clip lead; for use up to approximately 100 MHz.
Model 91-SB, 50Q BNC Adapter. Used for measurements up to
600 MHz with a SO-ohm system; for V5WR see curve of Figure 3.
Warm-up period, 1 min. Adjust zero on 1 mV range when measur¬
ing below 30 mV.
Mode! 91-6C, Unterminated BNC Adapter. Used for coaxial con¬
nection up to approximately 100 MHz, or to 400 MHz when fed
from a 50-ohm source in an electrically short system.
Model 91-7C, 100:1 Voltage Divider. Attenuates input signal by
a factor of 100 (± 1%), permitting measurements up to 300 volts
and extending the rms measuring range to 3 volts; increases input
resistance by a factor of 1000; operates from 50 kHz to 700 MHz.
Maximum input potential, 1000 volts, dc plus peak ac.
Model 91-14A, 5CX^ Tee Adapter. Type N Tee Connector; with
Model 91-1 5A termination (see below) permits connecting into 50-
ohm 1 ine; required for measurements above approximately 1 00MHz;
for VSWR see curve of Figure 4.
Model 91-15A, 50Q Termination. Type N 50-^hm termination for
use with Model 91-14A Tee Connector.
Model 91-18A, Storage Cose, Case for protecting and storing
Model 92A accessories.
Mode! 91-4C: Special 1 kHz to250MHz RF Probe. Low Frequency
probe for measurements ranging from 1 kHz to 250 MHz; input re¬
sistance essentially the same as that of Model 91-12F, RF Probe.
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Other
Accessories
(Optional)
Available:
(cont'd)
Standard
Equipment
Options:
Model 91'-16A, Unterminated Type N Adapter. May be used with
all probes, except Model 91-23A. Used for coaxial connection
up to approximately 100 MHz, or to 400 MHz when fed from o 50-
ohm source in an electrically short system.
Model 92-lA, Single Rack Mounting Kit. Kit for mounting one
92A/AB as one-half of a module tn a standard 19-inch rack.
Mode! 92-1B, Double Rack Mounting Kit. Kit for mounting two
92A/AB*s side-by-side in a standard 19-inch rack.
Mode! 92AB-02. Logi c-level programming, with 8-line logic level
input, TTL/DTL compatible.
Model 92AB“03. dBV option, dB scale, referred to 1 volt.
Model 92AB-04. dBV option, dB scale, referred to 1 volt, is read
out at top scale on meter.
Model 92AB-05. 75Q dBm option; dBm scale, referred to 75Q^
Model 92AB-06, 75Q dBm option; dBm scale, referred to 75Q,
read out on top scale on meter.
Model 92AB-07. 50Q dBm option; dBm scale, referred to 50Q,
read out on top scale on meter.
Model 92AB-08. Rear signal-input option.
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SPECiFiCATiONS (Cont’d)
IMPORTANT NOTE:
Fully to exploit the capabilities of this instrument,
the accessories listed below are required for the
indicated ranges of operation.
Table 1 . Required Accessories
MEASURING RANGE
100 MHz to 600 MHz
REQUIRED ACCESSORY
Model 91-8B 50Q Adapter for
shielded connection to 50-ohm
line; other impedances avail¬
able on request.
REMARKS
Supplied as standard
equipment with the
Model 92 Series.
Above 600 MHz
Mode! 91-14A Tee Connector
and 91 -15A 50 Q Termination
for connection Into 50-ohm
line.
Available separately.
1 kHz to 250 kHz
Model 91-4C RF Probe
Available separately.
Input levels up to 300V;
rms re^onsewith levels
to 3V.
Model 91 “7C 100:1 Voltage
Divider; operates over frequency
range from 50 kHz to 700 MHz
Available separately.
For details on the availability of these and other Boonton Electronics Accessories for RF
Voltmeters, call your local Boonton Electronics Sales Engineering Representative, or
write directly to the factory at the address on the title page of this instruction bookc
Table 2. Crest Factors
VOLTAGE RANGES (mV) AND CREST FACTORS
VOLTAGE
RANGE (mV)
1
3
10 30 100* 300*
1000*
3000*
CREST
420 70 21
7
420
70 21
7
FACTOR**
to to to to to to to
to
42
14
4.2
K4
42 14
4.2
1 A
* With accessory 100:1 Voltage Divider (see Table!)
**Maximum permissible ratio of peak to rms value of voltage
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INPUT
RESISTANCE,
OHMS

0.01
0.03 0.05
0.1
0.3 0,5
RF TEST VOLTAGE.(V)
3.0
Figure 2. Input Capacitance vs. input Level of Mode! 91-12F Probe (Measured at 10 MHz)
200 300 400 500 600
MHz
Figure 3. Typical VSWR of Model 91-12F RF Probe with Model 91-8B 500 BNC Adapter
830352
:
1
m/m/m.
rrrrTTI?,
7////////.
V//N0N
' / ! l-i-i
UJiU
1
Wf.
TIu
'mL
7 / / / / ,
iUjJ^
7///.
rrrr
'///
ttt;
a
_1
'll.
ilk
200 300 400 £00 700
MHz
Figure 4, Typical VSWR of Model 91 -12F RF Probe with Model 91 -14A Type N Tee
Adapter and Model 91-15A 500 Termination
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CHAPTER Ml
OPERATION
3.1 INSTALLATION
The Model 92 has been inspecfed and tested at the factory before packing, and
is shipped ready for operation. If there is any indication of shipping damage, immedi¬
ately notify the carrier before attempting to put the instrument into operation.
3,1.1 Operating Controls and Indicators
The controls and indicators of the 92A are shown in Table 3A, and those of the
92AB in Table 3B.
Table 3A. Model 92A Controls and Indicators
ITEM
FUNCTION
PWR ON
This switch turns on the instrument power.
FULL SCALE These range pushbuttons, (1 , 3, 10, 30, 100, 300,
1000, and 3000 mV) and (-50, -40, -30, -20, -10,
0, +10, and +20) select the operating range.
A4 1/2-inch taut-band meter with two linear volt¬
age scales reading out 0 to 3 with 0.05 per divi¬
sion and 0-10 with 0.1 per division; and one log¬
arithmic dBm scale reading out -10 to 43 with 0.2
per division maximum.
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Toble 3A. Model 92A Controls and Indicot-ors (Con'f)
ITEM
PROBE
(Jack)
ZERO
(Control)
The following items are on
Fuse Holder and Fuse
Slide Switch
Recorder Output Terminals
Component Holders (Clips)
REMOTE CONNECTIONS
(Use with an Amphenol
225-2221-101 connector
or equivalent)
FUNCTION
The probe cable connects to the instrument through
this PROBE jack. Always be sure that the knurled
ferrule nut of the probe cable connection is tight¬
ened when in use.
This control is used to zero the instrument.
the rear pane!:
A fuse holder is located on the rear panel for in¬
stalling either a 0.15 ampere, 115V, or a 0.1 am¬
pere, 220 V, Bussman MDL SLO-BLO fuse.
Switch which is set to 115 V or 230 V, according
to the available power source. Be sure that the
proper fuse is located in the fuse holder.
A IX voltage proportional to the indicator reading
is available at these terminals,
F.S, output 4-1OV
Output Impedance = 9 kD
Three component holders or component clips are
located at the rear panel for securing accessories
which are not in use.
A card edge connector is mounted at the rear of
the instrument. See Figure 10 for the pin designa¬
tions.

Table 3A. Mode! 92A Confrols and Indlcafors (Con't)
ITEM
(Symbol on Rear
ITEM
Power Switch
FUNCTION
This safety requirement symbol has been adopted
by the International Electrotechnical Commission,
Document 66 (Central Office) 3, paragraph 5,3
Panel) which directs that an instrument be so labeled, If,
for the correct use of the Instrument, It is neces¬
sary to refer to the instruction manual. In this case
it is recommended that reference be made to the
instruction manual when connecting the Instrument
to the proper power source.
Verify that the right fuse is installed for the power
available and that the switch on the rear panel
0.15A and 0.10A, 50-400 Hz, is set to the appli¬
cable operating voltage of 115 V or 230 V. Within
a brief time, the use of this symbol will be acted
upon by ANSI (ASA).
Table 3B. Model 92AB Controls and Indicators
FUNCTION
This is a rotary switch controlling the operating
condition of the instrument.
CHARGEo In this position, the instrument isoff,
but the charging circuits are connected to the
power line. Charging time in this mode is 14
hours from zero to full charge.
LINE. This position connects the instrument to
the ac power line and turns it on.
OFF. In this position, both charging circuits
and instrument are off.
BATT. This position connects the instrument to
the internal batterypower supplyand turns iton.
B. CHK. This position connects the meter across
the batteries, through a series calibrating resist¬
ance. A reading of 7 or higher indicates that the
batteries are sufficiently charged for reliable oper¬
ation .
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Table 3B. Mode! 92AB Confrois and indicators (Cont'd)
ITEM
FULL SCALE
METER
PROBE
(Jack)
ZERO
{Control)
The following items are on
Fuse Holder and Fuse
Slide Switch
Recorder Output Terminals
FUNCTION
These range pushbuttons, (1, 3, 1 0, 30, 1 00, 300,
1000, and 3000 mV) and (-50, -40, -30, -20, -10,
0, 4-10, and +20) select the operating range.
A4 1/2-inch tout-band meter with two linear volt¬
age scales reading out 0 to 3 with 0.05 per divi¬
sion and 0-10 with 0.1 per division; and one log¬
arithmic dBm scale reading out -10 to +3 with 0.2
per division maximum.
The probe cableconnects to the instrument through
this PROBE Jack. Always be sure that the knurled
ferrule nut of the probe cable connection is tight¬
ened when in use.
This control is used to zero the instrument.
the rear panel:
A fuse holder is located on the rear panel for in¬
stalling either a 0.15 ampere, 115 V, or a 0.1 am¬
pere, 220 V, Bussman MDL SLO-BLO fuse.
Switch which is set to 115 V or 230 V, according
to the available power source. Be sure that the
proper fuse is located in the fuse holder.
A DC voltage proportional to the indicator reading
is available at these terminals.
F.S. output = +10 V
Output Impedance = 9 kO
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Table 3B. Model 92AB Controls and indicators (Cont'd)
ITEM FUNCTION
Component Holders (Clips) Three component holders or component clips are
located at the rear panel for securing accessories
which are not in use.
REMOTE CONNECTIONS
(Use with an Amphenol
225-2221 “103 connector
or equivalent)
A card edge connector is mounted at the rear of
the instrument. See Figure 10 for the pin designa¬
tions.
(Symbol on Rear Panel)
This safety requirement symbol has been adopted
by the International Electrotechnical Commission,
Document 66 (Central Office) 3, paragraph 5.3
which directs that an Instrument be so labeled, if,
for the correct use of the instrument, it Is neces¬
sary to refer to the instruction manual. In this case
it is recommended that reference be made to the
instruction manual when connecting the instrument
to the proper power source.
Verify that the right fuse is installed for the power
available and that the switch on the rear panel
0,15A and 0.10A, 50-400 Hz, is set to the appli¬
cable operating voltage of 115V or 230V. Within
a brief time, the use of this symbol will be acted
upon by ANSI (ASA).
3.2 OPERATING PROCEDURES
In the following paragraphs, the initial operating procedure for the 92is described,
as well as operating notes and recommended connection methods.