Electro-Metrics EM-6992 User manual

INSTRUCTIONMANUAL
NEARFIELD
PROBE
SET
BROADBAND
RESPONSB
MODEL EM-6992
--
fuELEcrRo-METRrcs

INSTRUCTION MANUAL
NEARFIELD PROBESET
BROADBAND
RESPONSE
MODEL 8M.6992
ELECTRO.METRICS. INC.
231Enterprise
Road,
Johnstown,
New
York12095
Phone:
[phone] Fax:[phone]
EMAIL:[email protected] WBB:http://www.electro-metrics.com
MANUAL REV.NO:EM6992-3.0 ISSUEDATE:NOVEMBER
04.1996

WARRANTY
ThisModel EM-6992
NearFieldProbe
Set
is warranted for a period of 12months
(USAonly) from dateof shipment
against
defectivematerials
andworkmanship. This
warranty islimited totherepairor replace-
mentofdefective
partsandisvoidif unau-
thorized repair or modification is at-
tempted.Repairsfor damagedueto mis-
useor abnormal operatingconditions will
be performed at the factory and will be
billedat our commercial
hourly rates.Our
estimatewill beprovided beforethework
isstarted.

Section
1.0
2.0
3.0
4.0
4.1
4.2
4.2.1
4.2.2
4.3
4.4
4.4.1
4.4.2
ELECTRO.METRICS
EM-6992
ThbleOf Contents
Title
Description
Specifications
Applications
Optional
EM-6990
BroadbandAmplifier
EM-6990
Description
EM-6990Specifications
Electrical
Mechanical
EM-6990 Operating
Instructions
DescriptionEM-6990
Battery
PowerSupply
ChargingThe Battery
ReplacingThe Battery
Cells
TypicalCalibration
Chart,
H-Field Probes
Page
4
4
4
4
5
6
7
5.0 l0
(EM6992-i)

DLECTRO-METRICS
EM.6992
DESCRIPTION AND USE OF ELECTRO-METRICS
MODEL El'4-6992 NEAR FIELD PROBE SET
1.0Description
TheEM-6992
Near
FieldProbe
Setis intended
to serve
as
a
versatileaid
for diagnostic
testing
of radiated
emissions
over
abroad
range
of frequencies
from below 100
kHz to above
I
GHz.Theprob.e
setconsists
ofthree
(3)
magnetic
fieldprobes,
two (2) electric
freldprobes,
20 cm extension
handie,and
custom
carrying
case.
lnaddition,
an
optional
EM-6990
broad-
band
pre-amplifier
is.
also
available
(Referto paragraph
4.0
for Description/Specifi
cations).
The three-
magnetic
field probes
areelectrically small (i.e.
resonant
frequency
above
I GHz) loops
of varyihgsensitivi-
ties.Theloops
are
woundwithin abalanced
Faraday
shield
thatreduces
theirresponse
to electricfields to a negligible
factor.
Each
successively
larger
loopincreases
sensitiiity 1in-
dependent
offrequency)
byapproximately
12
to 1
5dB. piobes
of reduced
sensitivity
may be of assistance
in isolating an
emission
source
moreprecisely.
A ballprobe
and
astub
probe
comprise
thetwo electric
field
probes.
Each
proberesponds
primarily to the electricfield
component
andrejects
themagnetic
field component.
TypeBNC (female)
connectors
are
used
asthe outputcon-
nector
onallthe
probes
plusthe
probe
extension
handle.
(EM6e92-1)

ELECTRO-METRICS
8M.6992
White theaccompanying
typicalcalibrationdata
assumes
that
the indicating instrument
presents
a 50-ohmimpedance
to
theprobeandconnectingcable,thisisby nomeans
manda-
tory.
Thehighimpedance
of anRFVoltmeter
oroscilloscope
maybeusedwith theprobes.
When making before-and-aftermeasurements
to determine
the effectivenessof an attemptedEMI solution, somscaJe
should be usedto ensurethat the measurementsarerepeat-
able.Of chief importance is thedistance from theprobe
to
theitem undertest.Evensmallchanges in thisspacing
can
yield largevariationsin amplitude.The E-field probes
are
alsosusceptibleto measurement
variationsdue
tocapacitive
couplingto external
objectssuchasequipment
chassis,
hu-
manbodies,largemetalobjects,etc.The H-field probes do
notexhibit thiseffect.
Theresponse
of the
E-fieldprobes
isessentiallyomni-direc-
tional. The response of the H-field probes
is a figure-8re-
sponse,typical of adipole.
Theprimarypickupdirection
is
broadsideto theloop,with sharp
notchesin thepickuppat-
ternin theplane
of theloop.
2.0Specifications
ModelEM-6993:
Connector:
ModelEM-6994:
Connector:
ModelEM-6995:
Connector:
6cmLoop,
H-fieldSensor.
BNC,female.
3cm
Loop,
H-fieldSensor.
BNC, female.
I cm Loop,H-field Sensor.
BNC,female.
@I/16992-2)

Model
EM-6996:
Connector:
Model
EM-699'7:
Connector:
ELECTRO.METRICS
EM-6992
3.5cm Ball,E-fieldSensor.
BNC, female.
0.3cm Stub,
E-field Sensor.
BNC,female.
3.0
Applications
Theprobeset
is designed
for usewith many differentindi-
catinginstruments
suchasEMI receivers,
spectrum analyz-
ers,
oscilloscopes.
Theselected
probe
isconnectsd
to thein-
dicating
device
usinga 50-ohmcoaxialcable(Model EM-
1107orequivalent).
Probechoice
isdetermined
bythe
typeof signal
underobser-
vation,signalstrength,
andthephysicalsizeof thearea
to be
investigated.
Comparison
oftheresponse
to both
H-field and
E-fieldprobes
will providetheuser
with some
ideaasto the
relative
magnitude
oftheE-fieldand
H-field of each
compo-
nent,
thus
providingacluetoward
solving
theemission
prob-
lem.
Thelarger
probesprovideincreasedsensitivity
while the
smaller
probes
permit
amore
preciselocationof the
emis-
sionsource.
(EM6e92-3)

ELECTRO.METRICS
EM-6992
4.0Optional EM-6990 Broadband preamplifier
4.1Description EM-6990
TheEM-6990Broadband
Preamplifier
isdesigned primarily
for usewith the EM-6992 ProbeSetin perfoiming EMI di-
agnostic
testing.The EM-6990 provides
a significant
im-
provementin overall measurement
sensitivity of thetypicat
spectrumanalyzenSmall sizeandinternalrechargeablcbat-
teriesmake
theunit suitable
for both
bench
andfieldtesting.
An externalbattery chargeris usedto recharge
the internal
batteries.
4.2 E'NI-6990
Specifi
cations
4.2.1
Electrical
Gain:
Bandwidth
(@-3 dB):
Frequency
Range:
NoiseFigure:
1
dBCompressionPoint:
Power
Source:
Operating
Time (approx.):
Recharge
Time:
Input/Output
Connectors:
25
dB,typical.
1199.995
MHz.
5kHz-1200 MHz.
6dB.
-1
dBm.
4rechargeable
"N"cells.
(1.2
VDCnickelcadmium)
15hoursbetweenrecharging.
14-16hours.
BNC, female.
(EM6ee2-4)

ELECTRO-METRICS EM.6992
BatteryCharger: 2Optionsavailable:
1)110VAC,
50160Hz
2\220VAC,50160
Hz
Size:
InsideDiameter:
2.1mm
Outside
Diameter:
5.5
mm.
Charge/Power
Jack:
NOTE
Therechargeable
nickelcadmiumbatteries
can
be
replaced
by4commonlyavailable
NoN-nr-
cTTARGEABLE
Alkaline "N" cells that increase
theoperating
timeto approximately100
hours.
Operating
Temperature:
4.2.2Mechanical
Length:
width:
Height:
Weight:
-20"C
to
60"C.
76
mm
(3")
89
mm
(3.5")
44.5
mm
(1.75")
230
g(10
ounces)
(EM6992-s)

ELECTRO.METRICS EM.6992
4.3EM-6990 Operating Instructions
TheEM-6990 Preamplifier
isnormallyinserted
inline
between
theprobe
beingused
andthereceiving
device
(e.g.
spectrum
analyzer,
oscilloscope,
etc).
Thetypical gain
of tlie
preamplifier
is approximately
25 dB producing
asignficant
increase
in the
overall
sensitivity
of the
typical
spectrum
ana-
lyzer.
Operation
of thePreamplifieris controlled
by aslide
switch
located on the side of the unit next to the externalcharser
iack.
CAUTION
The posrrroN
of the ON/OFF slideswitch
pRovrDES
TrrEoNLy
rNDrcATroN
whether the
EM-6990
PreamplifierrsoprRArrxc.
To
con-
servebattery life, always turn off the
preamplifier
whennotin use.
4.4Description EM-6990 Battery Power Supply
Theinternal
batteryof theEM-6990consists
of four (4) 150
mA-hour 1.2VDC nickel cadmium "N" cells.The fully
charged
batteries
will operatethePreamplifier
for approxi-
mately 15hours.
It will fully recharge
aftersuchusagein 14
to 16
hours.
(EM6ee2-6)

ELECTRO.METRICS
EM-6992
For longeroperatingtimes, the nickel cadmium "N" cells
canbereplaced by 4 commonly available
NoN-REcHARGE-
anm Alkaline "N" cellsthat increasethe operating
time to
approximately
100hours.
4.4.1
Charging
TheBattery
Torechargethe
internalbatteries,turnoff theEM-6990
and
connect
theexternal
batterycharger
tothe
CHARGER
JACK
located
on
thesideofthe
unit.
NOTE
Tomaximizethe
recharge
rate,
theunitshould
not
beoperated
whileconnected
tothe
exter-
nalcharger.
Inaddition,
operation
while
con-
nectedto theexternal
charger
couldcause
ground
loopsand
noise
problems.
WARNING
DONOTattempttoRE-CHARGEAL-
KALINE cells. The cells mrryrupture
and causeseveredamage to the am-
(EN/69e2-7)

ELECTRO-METRICS EM-6992
Twobatterycharger
optionsare
available:
1)110VAC,
50160Hz
2)220
VAC,
50t60Hz
Afterthebatterieshave
been
recharged,remove
theexternal
charger.Theunitisnowreadyforuse.
Storage
oroperationofthe
nickel
cadmiumbatterycellsator
neartheuppertemperature
limit (60"C) will significantly
reducethenumberof batterycharge/discharge
cycles.
Inaddition,operationofnickelcadmiumbatterycellsat
low
temperatures
(<-20"C)
will limit theiroperational
life.
4.4.2
ReplacingTheBatteryCells
Toreplace
thebattery
cells:
Turn off theEM-6990.
Remove
theeight
(8)screws (#0-80
x3/16 FLATHD)
from theedge of thetopcover.
Carefullyremove
theold cellsfrom theholders.
Replacement
cells:
RECHARGEABLE
NICKEL CADMIUM: Panasonic
P-15N
Radio
Shack
23-l2l
a.
b.
c.
d.
(EM6992-8)

NON.RECHARGEABLE
ALKALINE:
ELECTRO-METRICS EM-6992
SPC
BRN-N
Radio
Shack
23-030
Eveready
E90
Ray-O-Vac
8lC
Durcell
MN 9100
e.
f.
o
b'
Carefully
insert
the
newcells
into
the
holders,
ensur-
ingthat
thecells
are
placed
with respect
to there-
quired
polarity.
Check
the
inserted
cells
toensure
that
noshorting
of
the
battery
terminals
orwiring
hasoccurred.
Replace
the
topcover
and
screws
carefully.
Ensure
that
nowires
aretrapped/pinched
between
the
cover
and
case.
(EM6e92-e)

ELECTRO-METRICS
EM-6992
5.0
Tlpical Calibration
Chart H-FieldProbes
Thecalibration
chartofPagel1 shows
typicalantennacali-
bration
datafor the three
(3)H-Field probes
supplied
with
the
EM-6992
Probe
Set.
Three
typical
calibration
data
plots
areshown:
Upper
Plot: I cm
Loop,
MiddlePlot: 3cm
Loop,
LowerPlot: 6cm
Loop.
TheY-axis
is
denoted
indB(Sm-1;.
TheX-axis
isdenoted
in Frequency
(MHz).
dB(Sm-l)
= dBabove
1Siemens/meter.
Add
dB(Sm-1;
tometer
reading
indB(pV) toobtain
dBSi-
emens.
dB(Sm-1;
=dB(ptum).
dB(Sm-11
+51.5dB
=dB(pV/m)(Far
Field).
dBSiemens
+2dB
=dB(pT).
dB
Siemens
-158
dB
=dB
gauss.
(EM6ee2-ro)

ELECTRO.METRICS EM.6992
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(EM6ee2-11)

EI-ECTRO-METRICS
EM-6992
OTES

THIS INSTRUCTION MANUAL AND ITSAS.
SOCIATEDINFORMATION ISPROPRIETARY.
UNAUTHORIZED REPRODUCTION
IS FOR.
BIDDEN.
@rqgo
ELECTRo-METRrcs.
rNC.

PRINTED IN THE UNITED STATBS OF AMERICA
ELECTRO-METRICS, Incorporated
231EnterpriseRoad,
Johnstown,NY 12095
Phone:
(518)
762-2600 Fax:(518)
762-2812
EMAIL:[email protected]
WEB:http://www.electro-metrics.
com