Hi Albert,
I have traced the signal from the delay multiplier all the way to Q948 and beyond. It does have an effect on the signal at tunnel diode CR950, but with nothing to compare it to, I don't know if the levels are correct. As soon as I have some more free time, I'll take some measurements and post back with what it's doing.
Thanks,
Andy
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--- In TekScopes@..., "Albert" <aodiversen@...> wrote:
Hi Andy,
Did you already follow the Delay Time voltage in the Delay Pickoff circuit? My interpretation after looking at the schematics is as follows.
Check that U355 pin 6 and Q359A base follow the dial setting from about 5 V to about 13 V. If not then trace back (interrupted R350?).
Check that Q359B base receives the up-going delaying sweep voltage, see also TP400. At delaying sweep start, Q378 conducts and Q948 conducts and holds-off the delayed sweep start. When the comparator Q359A/B switches, Q378 blocks and Q948 blocks and allows the delayed sweep to start (either immediately or after the next trigger recognition).
Albert
To sum up the problems:
1. Delay multiplier acts like it's always at 0.0
---
Andy
