What are reasonable trigger thresholds? How small a signal will trigger the oscilloscope?

What are reasonable trigger thresholds? How small a signal will trigger the oscilloscope?

There are two specifications for trigger level: trigger level range and trigger level sensitivity. Both are written in terms of divisions. The trigger level range at any volts/division setting should be larger than the full scale range to allow examining waveform features that may be at a much different level than the desired trigger point. Trigger sensitivity defines the smallest waveform that will generate a stable trigger. Most Tektronix oscilloscopes will trigger on a signal of 0.35 divisions at up to 50 or 100 MHz.