Hi guys,
So, I bought some banana plugs, namely the type BUELA 20 K, made by HIRSCHMANN, made cables from them, plugged them in my Keysight 34461A, done my measurements... and one of the bastards won't come out.
I'd guess that the head is stuck, since the construction is such, that 6 plated bits are springy and when inserted make contact with the outer tube of the socket. The tip of the plug is a metal bit that holds them in place. This means that the diameter of the body of the plug can be smaller than the tip, when the springy bits are pressed into the body.
I'm guessing that the sockets in the Keysight device are a tube, but not all the way through - as such the head got caught on the end of the tube and the bastard won't come out. Bonus points if the head gets deformed by more frustrated attempts at pulling it out, making it more stuck.
So, yeah. This will be fun.
Attached are the photos of the culprit.