CurtPalme.com Home Theater Forum

[racerxnet]

Register to remove this ad. It's free!

Does anyone know how hot the tube housing gets on a A/C marquee? IR gun readout?

Thanks,

Mak

[Tim in Phoenix]

Hello

The core fans force air through the tube covers, but the tube face certainly warms up after a while. I have not seen any precise measurements on that.

[cmjohnson]

Without coolant, and driven hard, it can get hot enough to break the tube face via thermal expansion.

The good thermal conductivity of the aluminum casting filled with ethylene glycol pretty much guarantees that
whatever the casting temperature reaches, the tube face won't be too far from the same temperature.

So stick your thermocouple on the cooling fins on the casting and add a few degrees.


I don't know the exact value but I doubt it ever gets above 120 degrees. Call it 40 to 50 degrees above
ambient temperature.

[racerxnet]

Thanks guys,

The reason I ask is that Kurt suggested I block the stray light from the tubes. I made some tin shields and painted them flat black. Unfortunately they have little give and I am considering alternative materials to enclose the lens to tube housing. Just don't want to have a molten mess if it gets to hot.

MAK

[cmjohnson]

You'll be fine, it'll never get that hot no matter what!

Yes, it can only help matters to black out everything that the light from the CRT face can touch, except for the lenses, of course!

If you have an 8500, use flat black spray paint on the tube mount frames and lens mounts, and the upper and lower mounting plates as well.

On a 9500, when I replace the glycol in a tube I always paint the exposed aluminum surface in the LC chamber with VHT black epoxy paint, which not only helps control light and improve contrast, it also make the glycol last a LOT longer as it stops the glycol from eventually eating through the anodized coating and attacking the aluminum.