Crusty battery in Eico 221 tube multimeter.

[petemoore]

  How important to the DC operation is the decrodiated D cell ?
  There's also a recto-tube which I guess works, and a 6SN7GTB, and a transformer.
  And a thing about the diameter of a skinny little tube but is more like a black button...
  If I'm not working on it as a meter, other transformer questions may arise, it looks like a nice DC power supply, anyway.
  I wonder now what to do with it [?]
  And a thing about the diameter of a skinny little tube but is more like a black button...
  Anyway, it takes a while for it to warm up, then the meter moves, but the zero adjust, and the readings compared to my 9v battery are way off.