Applications
Measuring Millivolt Signals
With the standard, 10X-attenuation probes, deflection factors range down to
20 mV/division. To increase the vertical sensitivity by a factor of ten, either use a
1X probe or cascade CH 2 with CH 1. To obtain 200 juV/division, use a 1X probe
or coaxial cable to connect the signal to CH 2 and cascade CH 2 with CH 1. To
cascade CH 2 with CH 1:
1.
Connect the CH 2 output on the rear panel, through a 50-12 cable, to the
CH 1 input on the front panel.
2.
Set the CH 1 input at 1 Mfi DC or AC.
3. Set 20 MHz BW LIMIT on. This will reduce the trace "thickening" caused
by wide-band noise and avoid oscillation of the vertical system. If you
trigger from CH 1 source, you probably need to use HF REJ coupling.
4.
Set CH 2 VOLTS/DIV at 2 mV (20 mV with 10X probe) and set CH 1 at
5 mV or 2 mV/division.
5. Note that the CH 1 scale factor and delta-volts readings agree with the
signal at the CH 2 probe-tip with a 10X probe. With a 1X probe, the scale
factor and delta-volts readings should be divided by ten.
2465B/2455B/2445B Operators
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