7T11: Difference between revisions

Because the 7T11 and 7S11 have [[7000-series Sampling Shoe|direct interconnections side by side]], they also work in slow mainframes.  

The 7T11 supports up to two 7S11 for dual channel or X–Y operation.  

Due to its sampling principle (so called equivalent time sampling or undersampling), the 7T11 can only be used on repetitive signals and samples are always taken from signal portions delayed from the trigger event.  

This delay is adjustable on the front panel to select the portion of interest.  

At the three lowest time position ranges, the 7T11 changes from equivalent time sampling to real-time sampling.

To obtain maximum bandwidth, the sampling heads contain no delay lines, so the 7T11 needs an external pre-trigger if there are random, high-jitter signals or if the original signal triggered onto needs to be observed.  

In the special case of a periodic signal with low jitter, a [[random sampling]] mode can be used so that the signal triggered on can be observed.  

In this case, an internal PLL locks to the signal and generates an internal pre-trigger.  

To display the triggering event without slowing the sweep rate enough to see the next pulse, the input signal can be delayed by an external delay line such as the [[7M11]].   

X-Y operation is possible up to 14 GHz if one 7S11 resides in the A-horizontal slot of a 4-slot mainframe.

Additionally, there is an internal 200 MHz tunnel diode oscillator, which can be synchronized from external signals up to 14 GHz.   

This oscillator in turn drives a 10 MHz tunnel diode oscillator that provides the internal trigger signal.

Note that waveform acquisition with the 7T11 does not work in a [[7854]] mixed-mode scope because it uses the [[7000 Series plug-in interface|A1 sweep gate signal]] for blanking.