Gentlemen,
I've got this weird problem with the network analyser I posted about recently. The problem *seems* to be noise spikes on the DC voltage control ramp which are causing spurious spikes in the frequency domain on the RF output when viewed on an RF spectrum analyser. The peculiar thing is these spikes on the RF output are not random; they come and go according to the point the control voltage has reached as it ramps up. Curiously, I cannot see anything amiss with the ramp signal when I check it with a scope. I'd have expected to see at least *some* sign of instability, but it appears rock steady. I'm just wondering if an ordinary oscilloscope is really fast enough to pick out these transients, though. Maybe they're there even though I can't see them. Any suggestions as to what other instrument might be better suited to this purpose? A DSO, maybe? Or if not, optimising the settings on the analogue scope to have the best chance of spotting them? thanks!