Hello SI gurus, I was on si-list years ago when I was doing some optical line card hardware design. I've been doing other things recently, but a colleague of mine is having an issue, and I wonder if any of you have seen anything like this. We have a production test environment for 10Gbps lasers, which uses Anritsu pattern generators to generate signals to drive the lasers. We share a single PPG among multiple test fixtures, by - using DATA and DATA_BAR to drive separate fixtures - using an external 3db splitter (Picosecond Pulse) to split one of the outputs In total, we have 3 PPG's driving 8 test fixtures. There are external RF amplifiers, RF switches and bias-Tees connected as well. (Details are in the attached slides.) We're seeing that occasionally, the output of the Anritsu PPG gets "noisy" (that the best I can describe it; see the pictures in the attached slides). This never happened, over a 5-year period, until we recently upgraded our Anritsu PPG's to a new model. (MUT181020A) I suspect something with the output driver of the new Anritsu PPG. Perhaps when we switch the RF switches, there is a momentary impedance discontinuity, and thus a reflection back to the PPG, which puts its output into a "bad" state. The only way to recover the PPG so it generates a clean output again is to power cycle it. Has anyone seen anything like this before? Any suggestions on how to solve it would be greatly appreciated. - hwg ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu