purple tube heaters...

[vixr]

you guys ever seen purple tube heaters? Heater voltage is 5.7VAC

[7N7]

What types of valves are those?

7N7

[vixr]

6DJ8, 6N6Pi and 6V4 rectifier

[7N7]

Heater voltage is too low. Those valves should be run at 6.3v

7N7

[vixr]

OK... thanks for the advice 7N7. I will try that.

[vixr]

7N7, I just re-checked the heater voltage and its 7.5VAC...not 5.7...sorry for the bad data.

[7N7]

Aaaarrgghh!

That's even worse! Check your mains supply voltage and the setting on your equipment.

You will destroy the valves if you continue.

7N7

[kimjand]

I would have thought it was an artifact in the camera, as digital cameras have a high IR sensitivity, which shows up as purple in the resulting photo.

[7N7]

Originally posted by kimjand
I would have thought it was an artifact in the camera, as digital cameras have a high IR sensitivity, which shows up as purple in the resulting photo.

A good point, but it begs the question: why photograph the valves if they were not purple to start with?

7N7

[Merlinb]

In any case, digital cameras will photograph IR as white, not purple. (try taking a photo of the end of your TV remote while pressing the buttons!)
It rather looks as if the valves are gassy, or the cathode coating hasn't been mixed properly/has impurities (such as calcium carbonate, which will give off a blue-ish glow) Looks pretty cool!