Low Filament Voltage

nic37 · Post by **nic37** » Mon Feb 06, 2006 5:08 am

Hi. I´m getting a low reading (5.9 V AC) from my Tube rectified AC-50 filaments. I think It should be 6.3V AC. What´s wrong?

rictified · Post by **rictified** » Mon Feb 06, 2006 7:24 am

I would think that was close enough, voltages are very rarely exactly on in electronic equipment. Maybe your house voltage is a little low.

soundmasterg · Post by **soundmasterg** » Mon Feb 06, 2006 12:10 pm

I think most people would like to see from about 6v to 6.5v, but a little bit outside of that isn't abnormal. The AC wall voltage, at least in the US, changes all the time, going up and down at various times during the day. You could check your AC wall voltage with a meter to see where it is, but you are probably just fine at 5.9v.

nic37 · Post by **nic37** » Mon Feb 06, 2006 1:48 pm

Thanks guys.You´re right I measure 215V in the morning and 225V in the evening.

rictified · Post by **rictified** » Mon Feb 06, 2006 8:17 pm

I had an SVT head in Lima which was wired for 220 and the voltage there is around 220 most of the time. In the states the voltage is closer to 120, doubled would be 240, so the plate voltage was about 25-30 volts lower there than it is here. The head worked fine there and works fine here.

scott_s · Post by **scott_s** » Sun Apr 02, 2006 11:32 am

For what it's worth, GE spec'd heater voltages for their power tubes at 6.3 +/- 0.6V. I'm guessing EL34's would be a similar story.