On 2019-04-16 1:08, Reed Dickinson wrote:
Hi Alberto:Hi Reed,
thanks for your answer. Yes, that is exactly what I did to obtain what is shown in my photo Nr. 2.
All normal and all well understood. But what I expected to see was a stable rising edge of the signal, as in the photo, taken with the 'scope cold, just switched on.
The problem is that when the instruments warms up, that rising edge is no more stable, the trace moves left and right, in a random fashion.
Clearly a problem related to the warming of the 'scope...
I will check, as you suggested, the voltages. There is a suspect tantalum capacitor, which I did not replace, namely C933, which is in the path that brings working voltage to the Delay Time Position control.... just as good measure, I will replace that also...
Thanks and regards