30mm symbol tube manufactured by Tesla

The ZM1041 is a special character indicator tube with red coating for better contrast. The character height of 30mm makes this tube a companion to numerical indicators like the ZM1040. Its a rare tube, beause it was produced in less numbers as the numerical indicators. I assume these tubes were used in measurement instruments. According to tesla's datasheet a clear-glass editon, the ZM1043, also exists. There is also a different version, the ZM1041S, with additional Symbols
Brand / Manfacturer Tesla
Same Types
Likely Tyes
Symbol height in mm 30
Characters / Symbols +,-
Decimal point none
Base / Socket B13B
Starting Voltage (typ) 170 V
Maintaining Voltage (typ) 140 V
Current per Segment 4.5mA
Reccomend Resistor 6.8kOhm = 4.5mA