Grayscale

Well, not much time to play with the projector lately. Here is a quick update.

Only a few movies with the temperature probe inside. It seems to run around 30C and climb to 46C after powerdown (as the fan stops cooling it for a little while).

I’ve been thinking about attempting the Solar Cell Gray Scale calibration procedure. This makes use of a ‘cheap’ solar cell and a multimeter to measure the light output and match the three tubes.

Of course, I needed to understand how to set grayscale on the CRT. After much thinking, I realized I had the information in hand. The RGB Adjust .pdf in the files section has everything I need to know.

Careful reading of this resulted in my understanding WHY the Ampro seems to have high brightness and contrast settings. The calibration procedure has the remote control settings set to 95% bright and 95% cont. No wonder you need to run with big numbers to get the ‘right’ image..

Cooling off..

Well, the projector seems to be getting fairly stable now. Also, with the end of winter weather, I can now turn the furnace off while watching a movie and hear the roar of the fans.. So its time to start thinking about taking care of that.

Papst (now ebm) seems to have the quietest fans, but they seem somewhat hard to get. Vantec also has quiet fans, and they are easier to get — so Vantec might be the choice.

For now, I’ve added a temperature probe to the SMPS (low volatage) power supply. I want to track how hot the unit gets during normal usage. It will be important data when I replace the small 60mm fan.

Ideally, I need to pull the existing fans and match the CFM and static pressure, but with quieter units. However, as long as I have enough cooling I’m happy — so lower spec fans might be ok.

The 60mm fan is the first one I’m going to change. There seems like there may be room for an 80mm fan in its place. This would allow for a quieter fan but one that pushes at least as much air as the 60mm fan. I’ll have to see, the 80mm fan might require some case modification.

I’d like to also add a fan to the HVPS which seems to get pretty hot. I’m sort of surprised that there isn’t one. Doing some maintenance on the HVPS is also in order.

The two 80mm fans also need to be replaced. The fan filters are still on as well, and I’ll want to remove those to increase the fan efficiency. In fact, the grills might go too — grills make noise due to air turbulence.

For now, I’ll run with the noisy fan(s) and measure some temperatures. Hopefully soon I’ll get some time to pull the existing fans and look up some specs.