The confusion is understandable. There are so many different variants of the FE-5680A, and they are not easy to identify.
Some of the information you see out there is from folk who measure the voltage on the pins with a meter, not understanding what they are looking at. When I've investigated such devices (I have several FEI units) I start by tracing my way back from the power supply regulators to determine where the power goes in, and what it should be, to avoid mistakes. It's also been a useful technique with things like GPSDOs where nothing is known about the pinouts (Trimble NTGS-50AA for example). Sure is frustrating when you have one that isn't frequency agile! One of my FEI units is an FE-5680B with only 1pps output. The Chinese supplier thought it was faulty, but the 1pps pulse is only 5us wide, and isn't present until the unit has locked. I found a very useful 60MHz reference inside the unit as well. 73, Murray ZL1BPU _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.