Testing Performance
2
7000 Series Oscilloscopes Service Guide
41
3
Set up the oscilloscope.
a
Press the
Save/Recall
key, then press the
Default Setup
softkey.
b
Press the
Acquire
key, then press the
Realtime
softkey to
unselect Realtime.
c
Set channel 1
Coupling
to
DC
.
d
Set channel 1
Imped
to
50 Ohm
.
e
Set the time base to 500 ns/div.
f
Set the Volts/Div for channel 1 to 200 mV/div.
g
Press the
Acquire
key, then press the
Averaging
softkey.
h
Turn the Entry knob to set
# Avgs
to 8 averages.
4
Set the signal generator for 1 MHz and six divisions of
amplitude.
The signal on the oscilloscope screen should be about five
cycles at six divisions amplitude.
5
Set up the Amplitude measurement
a
Press the
Quick Meas
key.
b
Press the
Clear Meas
softkey.
c
Press the
Select:
softkey and use the Entry knob to
select
Std Deviation
within the select menu.
d
Press the
Measure Std Dev
softkey.
6
Note the oscilloscope Std Dev(1) reading at the bottom of
the screen. (This is the RMS value with any dc offset
removed.)
7
Set the power meter Cal Factor % to the 1 MHz value on
the calibration chart on the power sensor.
8
Note the reading on the power meter and covert to Vrms
using the expression:
For example, if the power meter reading is 892 uW, then
Vin
1MHz
= (892*10
- 6
* 50
Ω
)
1/2
= 211.2 mV
rms
.
