background image

Subject to change without notice

20

C o n t r o l   e l e m e n t s          

Control elements

 OF (LED)

 

This LED is lit when an overfl ow ocurs. This 
depends on the selected gate time and on the 
frequency of the signal applied.

  GT (Gate Open; LED)

 

The gate indicator is lit when the gate is open 
for measurements. This time equals the pre-
selected gate time and a synchronization time. 
The gate cannot be open for a time smaller 
than 1 period of a signal.

  Gate Time (pushb LEDs)

 

The gate time is selectable in steps of 0.1s, 1s, 
10s.

  

EXT.  (LED)

 

In the GATE EXTERNAL position, the counter 
will expect an external control signal, and will 
not measure until such a signal is supplied.

  Display Hold  (push LED)

 

Depressing the DISPLAY HOLD pushbutton 
sets the display time to infi nity and freezes 
the last measurement result. A new measure-
ment can be initiated using the reset pushbut-
ton. Measuring will restart when Display Hold 
is switched off. Display Hold starts and stops 
counting in the TOTALIZE function mode.

 Function indicators

 

LEDs (Refer to “Measuring functions”)

 

Function  (pushbuttons)

 

The “left” and “right” pushbuttons select the 
desired function. The appropriate LED is lit 
when a function is selected. The default value 
when switching power on is Frequency A.

  OFFSET  (push LED)

 

The displayed value becomes the reference 
value. (Not available with the TOTALIZE func-
tion).

  RESET  (push LED)

 

Stops a measurement and clears the display 
in normal measurement mode. When de-
pressing the button in DISPLAY HOLD MODE 
the counter performs a single measurement 
(one shot) on release of the button. When the 
OFFSET MODE is activated, depressing RESET 
shows the reference value (which is the actual 
offset). Reset is active as long as the button is 
de  pressed.

  INPUT  C  (BNC-connector)

 

Frequency range: 100 MHz to 1.6 GHz.

 

Input impedance 50Ω.

 

Attention! Do not apply more than 5V (DC+AC 
peak) to this input terminal.

 DC (pushbutton) 

 

Selection of AC or DC coupling of the signal 

Summary of Contents for HM8021-4

Page 1: ...r s a l C o u n t e r H M 8 0 2 1 4 Handbuch Manual Manuel Manual Deutsch English Fran ais Espa ol 99 Washington Street Melrose MA 02176 Phone 781 665 1400 Toll Free 1 800 517 8431 Visit us at www Tes...

Page 2: ...cable HZ72 from HAMEG is suitable 2 Signal cables Basically test leads for signal interconnection between test point and instrument should be as short as possible Without instruction in the manual fo...

Page 3: ...rmation regarding CE marking 14 Universal Counter HM8021 4 16 Speci cations 17 Important hints 18 Safety 18 Used Symbols 18 Operating conditions 18 Warranty and repair 18 Maintenance 19 Operation of t...

Page 4: ...put A Input impedance 1 M maximum sensitivity 20mVrms Input C Input impedance 50 maximum sensitivity 30mVrms Time interval resolution up to 10 ps Offset mode over the entire measurement range Gate inp...

Page 5: ...ty normal triggering DC 80 MHz 20 mVrms sine wave 80 mV pulse 80 MHz 150 MHz 60 mVrms sine wave 20 Hz 80MHz auto trig 50 mVrms sine wave Minimum pulse width 5ns Input noise 100 V typ Coupling AC or DC...

Page 6: ...t or discon nection of the protective earth terminal is likely to render the instrument dangerous Intentional interruption is prohibited The istrument must be disconnected and secured against unintent...

Page 7: ...d rear frames After removal of the two screws at the rear of the module both chassis covers can be lifted When reclosing the module care should be taken that the guides engage correctly with the front...

Page 8: ...ng will restart when Display Hold is switched off Display Hold starts and stops counting in the TOTALIZE function mode Function indicators LEDs Refer to Measuring functions Function pushbuttons The le...

Page 9: ...led by an external source Triggering measuring and counting Power on test A practical test of the correct operation of the HM8021 4 is run automatically at power on As soon as power is applied the dis...

Page 10: ...r level setting The input signal is triggered from 50mV up to the maximum input voltage of 5V The input frequency for the C input must always be in the range from 100MHz to 1000MHz For frequencies low...

Page 11: ...ate time of 10sec Period measurement For measurement of the period duration the re ciprocal value of the frequency T 1 f is measured in seconds The signal is applied as for frequency measurement Time...

Page 12: ...and DISPLAY HOLD should be in OFF position 2 Apply a frequency standard of 1 5 or 10MHz to input A and adjust channel A trigger setting for a stable reading 3 Depress RESET and then GATE TIME for appr...

Page 13: ...the counter has recognized a 10MHz standard During the following 45 seconds the signal is measured and the HM8021 4 is recalibrated Finally the new calibrated unit automatically switches back to norm...

Reviews: