Siglent SDS1104x-e sample rate during pulse testing

[cncjerry]

I put Leo's pulser on my brand spankin new SDS1104x-e with the upgrade to a SDS1204x-e.  Looking at the pulse in the upper right with one channel on, I see 1.00GSa/S as expected. 

I then hooked up the trigger output of the pulser and fed it into CH2 thinking I would see if the scope did better or worse with a 2nd channel triggering it.  Both channels dropped to 500MSa/S.

I then wrote some complaints in this space before thinking of trying CH3.  So CH1 and CH2 share one ADC and CH3 and CH4 share the other.  It makes sense.

I'm seeing 1.79ns rise time triggering on the pulse and 1.80 when triggering on CH3, that which has the pulser trigger output.  I suspect the 1.79 vs 1.80 are essentially equal.  My 11801c measures the pulse as 28ps though it should be closer to 40ps.  I'd be curious to hear if others see much different than the ~1.80ns risetime from Leo's pulser on this scope.

Thanks

Jerry

[2N3055]

1.7-1.8 ns sound about right and is consistent with a performance of an average 200 MHz scope...

[blurpy]

This is from an original SDS1204X-E: