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/ManfacturerRFT / WF
Same Types
Likely Tyes
Symbol height (mm)30
Decimal pointnone
Starting Voltage (typ)170 V
Maintaining Voltage (typ)140 V
Current per Segment4.5mA
Reccomend Resistor6.8kOhm = 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!