Blue Lights Plexi

[Realeigo]

Hello

I just finished building my 2nd plexi
Voltages without tubes are good, about 450volts on pins 3 and 4
Heating is good too. (6,3v)

With tubes i havent measured yet, i switched it off a soon as i saw blue light.

Can anyone help me out, to find what is wrong?

(i dont have any pics sorry.)

[Steve Conner]

Did the blue light look similar to the attached pics? If so, that's quite normal, nothing to worry about.

If it's extremely bright, then it might mean that your bias is set too hot and the tubes are passing too much current. The anodes will start to glow red too in this case.

However, if the rectifier tube is flashing blue, that's bad It means you made a serious wiring error that shorted the B+ to ground, or the tube is bad.

[Realeigo]

Problem of the blue lighting is fixed, now i got bias issues, probably because the tubes have been burned out. im using the 1 ohm resistor trick to bias, but im reading only 0.010 Volts
Please advice!