background image

12

Subject to change without notice

onscreen. If calibrated measurements are desired it will be 
necessary to use a probe if the signal becomes 

>

40 V

pp

. Check 

the probe specifi cations in order to avoid overstressing. If the 
time base is set too fast the trace may become invisible, then 
reduce the time base speed. 

If no probe is used at least screened cable should be used, 
such as HZ32 or HZ34. However, this is only advisable for low 
impedance sources or low frequencies (

<

50 kHz). With high 

frequencies impedance matching will be necessary.

Non sinusoidal signals particularly require impedance matching, 
preferably at both ends. At the scope input, a 50 Ω termination is 
selectable with a maximum load of 0.5 Watt (5 V

rms

, or  in case of 

sine wave signals, 14.7 V

pp

). If proper terminations are not used, 

sizeable pulse aberrations will result. Also sine wave signals 
of 

>

100 kHz should be properly terminated. Most generators 

control signal amplitudes only if correctly terminated. 
For higher loads (up to 1 Watt; 7 V

rms

 or 20 V

pp

) HAMEG offers 

the  external 50 Ω termination HZ22.

For probes terminations are neither required nor allowed, they 
would ruin the signal. 

Probes feature very low loads at fairly low frequencies: 10 MΩ 
in parallel to a few pF, valid up to several hundred kHz. How-
ever, the input impedance diminishes with rising frequency to 
quite low values. This has to be borne in mind as probes are, 
e.g., entirely unsuitable to measure signals across high impe-
dance high frequency circuits such as bandfi lters etc.! Here 
only FET probes can be used. Use of a probe as a rule will also 
protect the scope input due to the high probe series resistance 
(9 MΩ). As probes cannot be calibrated exactly enough during 
manufacturing individual calibration with the scope input used 
is mandatory! (See Probe Calibration).

Passive probes will, as a rule, decrease the scope bandwidth 
resp. increase the rise time. We recommend to use HZ200 pro-
bes in order to make maximum use of the combined bandwidth. 
HZ200 features 2 additional hf compensation adjustments. 

Whenever the DC content is 

>

 250 V

DC

 coupling must be used in 

order to prevent overstressing the scope input capacitor. This is 
especially important if a 100:1 probe is used as this is specifi ed 
for 1200 V

DC

 + peak AC. 

AC coupling of low frequency signals may produce tilt.

If the DC content of a signal must be blocked it is possible to 
insert a capacitor of proper size and voltage rating in front of the 
probe, a typical application would be a ripple measurement. 

When measuring small voltages the selection of the ground 
connection is of vital importance. It should be as close to voltage 
take-off point as possible, otherwise ground currents may de-
teriorate the measurement. The ground connections of probes 
are especially critical, they should be as short as possible and 
of large size. 

STOP

  If a probe is to be connected to a BNC connector use 

a probe tip to BNC adapter.

If ripple or other interference is visible, especially at high sen-
sitivity, one possible reason may be multiple grounding. The 
scope itself and most other equipment are connected to safety 
ground, so ground loops may exist. Also, most instruments will 
have capacitors between line and safety ground installed which 
conduct current from the live wire into the safety ground. 

First time operation and initial adjustments  

Prior to fi rst time operation the connection between the instru-
ment and safety ground must be ensured, hence the plug must 
be inserted fi rst.

Use the red pushbutton POWER to turn the scope on. Several 
displays will light up. The scope will then assume the set-up, 
which was selected before it was turned off. If no trace and 
no readout are visible after approximately 20 sec, push the 
AUTOSET button.

As soon as the trace becomes visible select an average inten-
sity with INTENS, then select FOCUS and adjust it, then select 
TRACE ROTATION and adjust for a horizontal trace.

With respect to crt life use only as much intensity as necessary 
and convenient under given ambient light conditions, if unused 
turn the intensity fully off rather than turning the scope off and 
on too much, this is detrimental to the life of the crt heater. 
Do not allow a stationary point to stay, it might burn the crt 
phosphor.

With unknown signals start with the lowest sensitivity 5 V/cm, 
connect the input cables to the scope and then to the measu-
ring object which should be deenergized in the beginning. Then 
turn the measuring object on. If the trace disappears, push 
AUTOSET.

Trace rotation TR

The crt has an internal graticule. In order to adjust the defl ected 
beam with respect to this graticule the Trace Rotation control 
is provided. Select the function Trace Rotation and adjust for a 
trace which is exactly parallel to the graticule.

Probe adjustment and use

In order to ensure proper matching of the probe used to the 
scope input impedance the scope contains a calibrator with 
short rise time and an amplitude of 0.2 Vpp ± 1 %, equivalent 
to 4 cm at 5 mV/cm when using 10:1 probes.

The inner diameter of the calibrator connector is  4.9 mm and 
standardized for series F probes. Using this special connec-
tor is the only way to connect a probe to a fast signal source 
minimizing signal and ground lead lengths and to ensure true 
displays of pulse signals.

1 kHz – adjustment

This basic adjustment will ensure that the capacitive at-
tenuation equals the resistive attenuation thus rendering the 
attenuation of the probe independent of frequency. 1:1 probes 
can not be adjusted and need no such adjustment anyway. 

F i r s t   t i m e   o p e r a t i o n   a n d   i n i t i a l   a d j u s t m e n t s          

 incorrect 

correct 

incorrect

Summary of Contents for CombiScope HM2008

Page 1: ...200 MHz Mixed Signal CombiScope HM2008 Manual English...

Page 2: ...irective des equipements basse tension 73 23 CEE amend e par 93 68 CEE Angewendete harmonisierte Normen Harmonized standards applied Normes harmonis es utilis es Sicherheit Safety S curit EN 61010 1 2...

Page 3: ...ajous gures 14 Measurement of phase differences in dual channel Yt mode 14 Measurement of amplitude modulation 15 Triggering and time base 15 Automatic peak triggering MODE menu 15 Normal trigger mode...

Page 4: ...t voltage Time Base 2ns div 50s div Acquisition modes Single Refresh Average Envelope Roll Peak Detect Front USB Stick Connector for Screenshots USB RS 232 optional IEEE 488 or Ethernet USB Signal dis...

Page 5: ...range 0 250 MHz Coupling DC Level control range 10 10 div Horizontal Deflection Analog Time Base Operating modes A ALT alternating A B B Time base A 20 ns div 0 5 s div 1 2 5 sequence Time base B 20 n...

Page 6: ...rent positions A and B carrying C horizontal operating D and E operating at different angles F handle removal T shipping handle unlocked A A B B C C D D E E T F PUkT PUkT PUk PUk PUk PUk PUk PUk PUkT...

Page 7: ...may be 20 C to 70 C Please note that after exposure to such temperatures or in case of condensation proper time must be allowed until the instrument has reached the permissible temperature resp until...

Page 8: ...V SCALE VAR knob 34 Channel 1 Y de ection coef cient Y variabel and Y scaling setting 17 VOLTS DIV SCALE VAR knob 34 Channel 2 Y de ection coef cient Y variabel and Y scaling setting 18 AUTO MEASURE p...

Page 9: ...selection of PROBE ADJ square wave signal hard ware and software information and details about interface rear side and USB Stick ash drive connector 42 COMPONENT TESTER 2 sockets with 4 mm 47 Connecto...

Page 10: ...st be taken however when charging and discharging a large capacitor DC coupling is preferable with all signals of varying duty cycle otherwise the display will move up and down depending on the duty c...

Page 11: ...ursors may be used for measurement Measurement Adjust the rising portion of the signal to 5 cm Position the rising portion symmetrically to the graticule centre line using both Y and X positioning con...

Page 12: ...e ground connections of probes are especially critical they should be as short as possible and of large size STOP If a probe is to be connected to a BNC connector use a probe tip to BNC adapter If rip...

Page 13: ...mind The oscillosco pe vertical ampli ers are two separate ampli ers and do not constitute a true difference ampli er with as well a high CM rejection as a high permissible CM range Therefore please o...

Page 14: ...and Y signals af ter reading a and b off the screen is possible using the following formulas and a pocket calculator with trigonometric functions This calculation is independent of the signal amplitud...

Page 15: ...ime base variable or external triggering Reading a and b off the screen the modulation degree will result a b a b m bzw m 100 a b a b a UT 1 m and b UT 1 m When measuring the modulation degree the amp...

Page 16: ...ange the slope Positive or negative slope may be selected in auto or normal trigger modes Also a setting both may be selected which will cause a trigger irrespective of the polarity of the next slope...

Page 17: ...Insert a 100 resistor between the center conductor and the BNC connector If possible the coil should be shielded without creating a shorted winding Alternate trigger This mode is selected with SOURCE...

Page 18: ...time for most of the time the digital will not see the signal Also in analog mode the signal itself will be seen on the screen in real time whereas a digital can only show a reconstruction of the sig...

Page 19: ...er COMPONENT PROBE 40 and COMPONENT TESTER 41 The scope has a built in component tester The test object is connected with 4 mm banana plugs In this mode the Y ampli ers and the time base are turned of...

Page 20: ...pend strongly on the kind of FET With depletion type MOSFETs and all JFETs the channel will conduct if prior to testing the gate was connected to the source The Rdson will be shown As this can be very...

Page 21: ...ependent single event recording with Yt display Single Readout display sgl 4 Trigger independent continuous recording menu VERT XY with XY display XY Readout display XY 5 XY display of previously in Y...

Page 22: ...value of the sampling interval 1 sampling interval sampling rate 3 The signal frequency value is related to the highest sine wave signal frequency that can be captured with 10 samples per period realt...

Page 23: ...s shows a straight line in the position of the positive peak value and consequently suggest a positive DC voltage An alias may also take the form of a signal of much lower frequency beat frequency bet...

Page 24: ...rogram for USB connection test RS 232 The RS 232 interface has the usual 9 pole SubD connector Via this bidirectional interface the scope can be controlled remo tely or its settings may be transferred...

Page 25: ...ilable submenus In some modes various pushbuttons or INTENS operations are meaningless and will hence not cause a menu display STOP Please note If a menu is shown some other information dis played in...

Page 26: ...to leave the menu Thereafter only the signal display is activated and the FOCUS TRACE MENU pushbutton will blink as long as the readout is off Pressing the ashing pushbutton calls the Int Knob menu wh...

Page 27: ...hannel mode Yt in the section First time operation and pre settings One period of a sine wave is equal to 2 hence the dis tance between the two long CURSOR lines must be set to one period If the dista...

Page 28: ...will be lost after turn off Mathematics offers 7 1 Equations set Using the INTENS knob 5 sets of formulas can be selected for editing This way 5 user de ned formula sets may be created Each set of fo...

Page 29: ...he display of the former The display will remain on screen until the next acquisition is started by the trigger and causes a new recording This mode is available over the full time base range 50 s cm...

Page 30: ...size is 0 25 s between the samples at a time base setting of 50 s cm The advantage of Peak Detect is that signals are sampled with the highest possible sampling rate to reduce the gap size so that eve...

Page 31: ...RE1 RE1 the signal will be displayed twice on the same spot Associated settings Pressing this function key causes the oscilloscope to take over the settings parameter stored when the signal was store...

Page 32: ...s will remain The digital modes Roll Envelope or Average will be changed to refresh mode AUTOSET will further set the intensity to an average value if it was set too low If a menu was opened it will b...

Page 33: ...control if Yt mode time base mode is present and the CH1 2 CURSOR MA REF ZOOM pushbutton 15 is not lit 14 1 2 Y Position of the FFT display only in digital mode measured with channel 2 Position 2 allo...

Page 34: ...he CH1 menu the de ection coef cient becomes calibrated the CH1 VAR pushbutton 31 does not light any longer and the VOLTS DIV SCALE VAR knob 16 returns to 1 2 5 sequence 16 3 Scaling the FFT display d...

Page 35: ...at V rms the range is from 5mV cm to 20V cm also switched in 1 2 5 sequence Please note that in contrast to Yt and XY mode signal display no peak to peak values but rms values are displayed 18 AUTO ME...

Page 36: ...me base set B trigger to positive or negative slope Thereafter the LEVEL A B control will control the time base B trigger a second trigger point symbol will be shown and marked with B 19 2 FFT mode Th...

Page 37: ...mpli er bandwidth and consequently less trigger signal noise Readout Tr Source Slope AC or DC NR 21 1 2 Slope SLOPE determines whether the rising or falling portion of a signal shall trigger the level...

Page 38: ...5 External In this mode the trigger signal comes from the AUXILIARY INPUT TRIG EXT 38 Readout Tr ext Slope Filter 22 1 6 AC Line The trigger signal is taken from the line mains supply which feeds the...

Page 39: ...ither reference nor mathematic signals are displayed The expanded portion of the signal will be shown on the normal display as an intensi ed sector The length of this sector is dependent upon the sett...

Page 40: ...ave form become digitised and at least show spectrum displays spectra that do not exist in reality If the sampling rate is too low the readout displays ALS if the signal is too high overrange will be...

Page 41: ...nly B The TIME DIV SCA LE VAR knob then only affects time base B By aid of the MAG x10 pushbutton 29 the signal display can be expanded 10 fold reducing the time de ection coef cient by factor 10 30 1...

Page 42: ...sensitivity setting is for AC and is for DC 31 1 1 DC coupling The signal will be directly coupled from the BNC connector via the attenuator to the vertical ampli er The input resistance is 1 M in all...

Page 43: ...DUAL trace alt chop In dual trace mode both channels are turned on and the para meters of both are shown in the readout Between the sensi tivity indications there is an indication whether alternate al...

Page 44: ...It is recommended rst to look at the signals in DUAL mode and to set the sampling rate such that at least one signal period will be displayed Then XY should be selected In XY digital mode both channe...

Page 45: ...he VOLTS DIV SCALE VAR knob 17 returns to 1 2 5 sequence switching and CH2 to calibrated condition 34 INPUT CH1 BNC connector This is the CH1 signal input connector In Yt mode it is a Y input in XY mo...

Page 46: ...accuracy of the FFT calculations in the following averageing process Numbers between 2 and 512 can be chosen by aid of the INTENS 2 knob which are displayed by the readout e g avg 256 The accuracy in...

Page 47: ...ive is connected with the USB Stick connector 43 41 4 1 USB Stick Save Front Panel current oscilloscope parameters The current parameters are saved on the USB ash drive by pressing the function key Sa...

Page 48: ...D 63533 Mainhausen A Rohde Schwarz Company Tel 49 0 61 82 800 0 DQS Certi cation DIN EN ISO 9001 2000 Fax 49 0 61 82 800 100 Reg Nr 071040 QM sales hameg com w w w h a m e g c o m 41 2008 00E1 authori...

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