Slightly corroded VNA ports?

[jmdlok]

The VNA I'm currently using has some oxidization/corrosion on the outer rim of the ports. I wonder if this will have an effect on measurements taken? (I have no idea how the corrosion happened)

In my mind, the wavelength of frequencies is naturally much larger than the tiny pits caused by the corrosion, so there shouldn't be huge issues. Also, a cal engineer has said that this shouldn't be an issue. Is this true/reliable?

 

[VEBill]

Corroded connectors can cause issues at DC, so the wavelength argument is a bit of a red herring.

That said, as long as the corrosion is cleaned off (and the contact metallurgy[sup][1][/sup] remains reliable on the points of contact), and the connectors haven't materially changed in their critical dimensions[sup][2][/sup], then it's probably okay.

1. Contact metallurgy is not something I know anything about, except that I've learned that it's a far more complex topic than most of us might be aware.
2. Keep in mind (as you'll already know) that the impedance for coax is related to the ratio of OD and ID (diameters) of the conductors.

You could run some tests on known-good items to make sure that everything is working as expected.

 

[jmdlok]

Corroded connectors can cause issues at DC, so the wavelength argument is a bit of a red herring.

It's a VNA so it won't be getting used anywhere near DC. It's minimum operable frequency is probably hundreds of Hz away from DC... Or am I misunderstanding your answer?

 

[VEBill]

"...the wavelength of frequencies is naturally much larger than the tiny pits caused by the corrosion, so there shouldn't be huge issues."

Translated to DC: "The wavelength of DC is infinite, so corroded contacts shouldn't be an issue, ever, at DC." Which clearly isn't really true.

So beware of the 'wavelength logic' as quoted. It might provide false assurances.

As mentioned, it's probably okay. Just be cautious and skeptical. Good luck.