Thank you, Klaus.
Test results:
When I first connected the mic today, the signal was nice and clean. (...as nice as MY voice can sound.)
Then I performed the breath test. First breath or two, I couldn't make the capsule collapse and everything still sounded great. So I gave it a nice strong steady "hhhhhhuuuuuuuhhhhhhhh" at very close range. This collapsed the capsule, (a big "poof" sound like I'd hear when switching polar patterns). Then the noise appeared. (The solar wind). As I type this, the solar wind is subsiding, but is still barely audible 3 or 4 minutes after the breath test.
How to proceed? Do you clean ck12's? (I dread to re-skin...)