The nice thing about the 8950 and the M-2057 are that these tubes give you a pair of 1 amp fusible cathode links on pins 2 and 6. You get two chances to destroy each of those tubes.We call this the "blown fuse" syndrome.
The 8950 tube seems to be susceptible to this sort of failure.
This one was.
Learned to eyeball that thin link from pin 3 to the cathode at the center of the tube before even bothering to put it into the tube tester.
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