What are reasonable trigger thresholds for the external trigger?

What are reasonable trigger thresholds for the external trigger?

Because the external trigger is not necessarily displayed, it is usually defined in terms of volts rather than divisions. There are usually at least two attenuation settings that you can apply to the external trigger. This provides for a wider range of trigger levels. In general, a 100 mV signal applied to the external trigger input will trigger a Tektronix oscilloscope.