Talk:7T11: Difference between revisions
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In the mean time I was able to repair me 7T11 and made some tests therefore. | In the mean time I was able to repair me 7T11 and made some tests therefore. | ||
1. A 100ps pulse train with 30MHz rep. was feed through a S6 head to ext. 50 Ohm. Sequential trigger performed well. But random mode did not work correct, but sometimes a impulse was stable visible with signal portions appearing at "negative" positions, forming loops into the impulse. | 1. A 100ps pulse train with 30MHz rep. was feed through a S6 head to ext. 50 Ohm. Sequential trigger performed well. But random mode did not work correct, but sometimes a impulse was stable visible with signal portions appearing at "negative" positions, forming loops into the impulse or bend to the left, so risetime has to read as 0pS. | ||
2. A 100ps pulse train completely random (noisy, "full period jitter") was then used. Sequential trigger showed a random pattern in time and amplitude, as predicted. Surprisingly in random mode there was a | 2. A 100ps pulse train completely random (noisy, "full period jitter") was then used. Sequential trigger showed a random pattern in time and amplitude, as predicted. Surprisingly in random mode there was a impulse visible, but verry noisy and no samples outside +-50nS! This is not declearable, because the internal prediction circuit can not foresee the next event! | ||
Someone an idea about the strange behavior? | Someone an idea about the strange behavior? | ||
--[[User:GHz|GHz]] 09:24, 31 March 2010 (UTC) | --[[User:GHz|GHz]] 09:24, 31 March 2010 (UTC) | ||
Revision as of 09:10, 31 March 2010
Random trigger mode
I am confused about this feature of the 7T11, because it further needs a periodic signal to synchronize and predict the next trigger event. So this job can be done in normal sequential mode too.
In the mean time I was able to repair me 7T11 and made some tests therefore.
1. A 100ps pulse train with 30MHz rep. was feed through a S6 head to ext. 50 Ohm. Sequential trigger performed well. But random mode did not work correct, but sometimes a impulse was stable visible with signal portions appearing at "negative" positions, forming loops into the impulse or bend to the left, so risetime has to read as 0pS.
2. A 100ps pulse train completely random (noisy, "full period jitter") was then used. Sequential trigger showed a random pattern in time and amplitude, as predicted. Surprisingly in random mode there was a impulse visible, but verry noisy and no samples outside +-50nS! This is not declearable, because the internal prediction circuit can not foresee the next event!
Someone an idea about the strange behavior?
--GHz 09:24, 31 March 2010 (UTC)