开云体育

That was my conclusion. But the UI is so bad that I thought there might be a variable delay line in there somewhere that would adjust channel skew. I've also discovered it is buggy as all hell. You pretty much have to reinitialize the scope for a bunch of operations. I tried switching from vector to dot mode. Menu said vector was off, but the display said otherwise. Once I initialized the scope I was able to set it to dot mode.

I've had the 11801 running for 4-5 hours with the calibrator feeding an SD-22 with cursors set on the peaks of the reflection in the cable. I've noticed that the internal timebase varies by a little over 1 ps over the course of 5-10 minutes. I have a postit on the screen and the cursors are not moving. The waveform is moving. I've got the internal clock output connected to my 5386A with the OCXO option and that confirms the internal time base period is changing.

From looking at the block diagram in the service manual, it appears to me that the OCXO is not as stable as the one in my 5386A which I have compared to a GPSDO over long periods.

This has me considering whether installing one of Leo Bodnar's single output GPSDOs in place of the 200 MHz OXCO would be worthwhile. In particular in improving the jitter spec from the factory 1.1 ps.

Watching the clock period vary by 100 femtoseconds over the course of 15-30 seconds with a 1 s gate time is rather interesting.


Reg

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