Non-noise instabilities in oscilloscope trigger circuits

The paper discusses two phenomena called tremor, which result in incorrect operation of the oscilloscope trigger circuits. Both of them change delays introduced by the trigger circuit, resulting in horizontal shifts of traces on the screen, but the origins of the two phenomena are different. Both kinds of tremors in the oscilloscope trigger circuits produce images on the screen, which often are similar to those resulting from the noise jitter. Hence, limited knowledge of tremor may be a source of improper interpretation of the oscilloscope measurements. On the other hand tremor can be considered as a different approach to the problem of flip-flop circuit's metastability.