30mm numeric tube manufactured by RFT / WF

The Z5660M is a 30mm numerical indicator tube manufactured by WF/RFT company. The size of the digits is 30mm and the glass is not coated. This is one of the most beautiful 30mm tubes, because of the curved glass shape and the true form digits. This tubes were used in digital measurement devices ( eg. voltmeters, frequency-counter) along with the special character type Z5670M
Brand / Manfacturer RFT / WF
Same Types
Likely Tyes
Symbol height in mm 30
Characters / Symbols 0-9
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


The tube shown on the pictures below has a small defect/bug. As you can see, the wires that connect digits to pins are glowing to. This is not normal, usually those do not glow!