Hameg Instruments HM 8021-3 Manuel page 16

1
2
3
(1)
OF (LED)
This LED is lit when an overflow occurs. This depends
on the selected gate time and on the frequency of the
signal applied.
(2) GT (Gate Open; LED)
The gate indicator is lit when the gate is open for
measurements. This time equals the preselected
gate time and a synchronization time. The gate
cannot be open for a time smaller than 1 period of a
signal.
(3) Gate Time (Gate time selector; pushbuttons+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.
(4) Display Hold (pushbutton + LED)
Depressing the DISPLAY HOLD pushbutton sets the
display time to infinity and freezes the last
measurement result. A new measurement can be
initiated using the reset pushbutton. Measuring will
restart when Display Hold is switched off. Display
Hold starts and stops counting in the TOTALIZE
function mode.
(5) 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.
(6) Offset (pushbutton + LED)
The displayed value becomes the reference value.
(Not available with the TOTALIZE function).
(7) Reset (pushbutton + LED)
Stops a measurement and clears the display in
normal measurement mode. When depressing 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
16
5
4
8 9
6 7 10
is the actual offset). Reset is active as long as the
button is de-pressed.
(8) INPUT C (BNC-connector)
Frequency range: 100MHz to 1.6GHz.
Input impedance 50Ω.
Attention! Do not apply more than 5V (DC+AC
peak) to this input terminal.
(9) DC (pushbutton) (DC coupling = button depressed)
Selection of AC or DC coupling of the signal input A.
The bandwidth for low frequencies is as low as 10Hz
(3dB) when the input is AC coupled. (Input C has a
fixed AC coupling).
(10) 1:20 (pushbutton)
Selection of input signal attenuation. Pressing this
button attenuates the input signal by 26dB before it
is applied to the input amplifier.
(14) 8 digit display (7 segment LEDs, 7.65mm high)
for the measuring result (8 digit max. + exponent).
(11) Auto Trigger (AC) (pushbutton)
With Auto Trigger active the counter triggers in the
middle of the input signal. Auto Trigger always
uses AC-coupling. (AC = pushbutton depressed).
(12) INPUT A (BNC connector)
Signal input with a sensitivity of 20mV up to 80MHz
and 60mV up to 150MHz. The input is protected
against overvoltage up to 400V (DC+ACpeak).
Input impedance: 1MΩII40pF.
(13) TRIGGER LEVEL (adjusting knob)
Continuously adjustment of trigger level.
TRIGGER (LED) 3 State trigger indicator. The LED
flashes when triggering is correct. The LED lights
when the trigger level is above the input signal level,
it is not activated when the trigger level is below the
input signal level.
(14) 8 digit display (7 segment LEDs, 7.65mm high)
for the measuring result (8 digit max. + exponent).
(15)Hz: (LED) Indicates the measurement of a frequency.
Sec: (LED) Indicates the measurement of time.
(16) External Gate Input (BNC connector)
Allows the measurement of the input signal,
controlled by an external source.
Änderungen vorbehalten / Subject to change without notice
11 12
15
14
13