Teledyne DA1855A, Operator'S Manual

Page: 32 / 94

DA1855A Differential Amplifier
26 922258-00 Rev A
Make these settings:
PVG Mode OFF
+Coupling
DC
–Coupling
Grounded (OFF)
DA1855A (Atten/Gain)
Auto
List Select: Upper BWL Full BWL
List Select: Gain
X1
List Select: Atten ÷ 10
List Select: Input R 1 M
Ω
Attenuator and Gain Operation
Connect the function generator output to the +INPUT BNC connector and apply a sine wave of 50
kHz and 1.0 Vp-p amplitude. If necessary, set the oscilloscope scale factor to 0.50 V/div. The signal
on the oscilloscope should be 2 divisions peak to peak. Adjust the oscilloscope’s time per division
and trigger to display at least two complete cycles of the waveform.
Set the DA1855A Atten/Gain to Manual. In the List Select menu, select Atten and in the Value menu
select /1. The waveform’s magnitude on the oscilloscope’s display will increase by a factor of 10, to
50 mV/div, the waveform will extend and extend off the top and bottom of the screen. The X1 light
will be lighted in the EFFECTIVE GAIN front panel display. Reduce the function generator’s output
until the oscilloscope’s display is again 2 divisions peak to peak.
Set the gain to X10. Observe the following changes: The +INPUT’s DC light will momentarily go out
and its OFF light will be lighted before returning to their previous states. This momentary change is
the result of the DA1855A automatically adjusting its DC Balance. The X10 light will be lighted in the
EFFECTIVE GAIN display and the display on the oscilloscope will again extend off screen. The overall
sensitivity of the DA1855A and the oscilloscope is now 5mV/div.