This tube has no manufacturer listed on the back, but the manufacturing code indicates it was made at the Philips Heerlen factory. It is a small symbol nixie tube that was intended to be used with the ZM1000 range of nixies. One of the symbols is a spiral. I have read (somewhere!) that these were possibly used to indicate an error condition or unknown state.

The pin layout of this series of tubes is quite interesting. It is laid out in a grid with a 0.1″ spacing. Most tubes use a circular pattern.

Digit size 14mm
Current 2.5mA
Base Eurogrid

Philips marked all of their tubes with identifying codes, so it is possible to figure out where and when this tube was made. The format of the markings on this tube is:


  • TTT is the type code (MRR in this case)
  • C is an internal batch code (0TT in this case)
  • F is the factory code (the triangle means Philips, Heerlen).
  • Y is 3, which could mean 1973 or 1963
  • M is J which means October

This site does a good job of explaining the codes.


ZM1003 Datasheet