CurtPalme.com Home Theater Forum

**kal** · Posted: Mon Feb 12, 2007 5:17 pm Post subject:

I think the big problem is the lack of static pressure and overly optimistic ratings by the manufacturer. In other words, the fans don't put out what they say they do and if you put any resistance in their way, the CFM drops greatly.

Read this post: http://www.avsforum.com/avs-vb/showthread.php?p=9740646&&#post9740646

WTS · Joined: 08 Mar 2006 Posts: 1276 Location: Calgary

Hi Kal,

Yes I agree about the static pressure capablity of the fan is very important, especially if you're pulling air through any restrictions. The 1200x layout has very little restrictions from what I can see. I guess the bottom line for me is after running it for 7hrs and I can still touch the heatsinks and they barely feel warm the the cooling is just fine. I've touched enough heatsinks over the past 25 years to know if they're running too hot or not for the electronics attached to them.

Walter

**kal** · Posted: Mon Feb 12, 2007 9:01 pm Post subject:

WTS · Joined: 08 Mar 2006 Posts: 1276 Location: Calgary

Hi Kal,

No, my pj is ceiling mounted. Looking at the pics it does look like there is some blockage, hmmm I don't recall seeing that in mind but it must be the same. Actually I meant not very restrictive as far as air flow from the front around the lenses thru the cage and then out the back of the cage. From the front to the back of the cage is fairly clean for air flow. Maybe you should get in there and do some metal reworking, it looks like you have a nice open area. Did you stripe down the whole pj before you put the hushbox on?

When I changed my fans I was quite aware of the fact that the static pressures weren't speced on the silenx fans which usually means they aren't that good. That goes for anything, if the spec is missing it's for a reason.

Yes running it at 1080i/60 is probably one reason why it's running cool. I'm not too concerned with the temps mine is running at.

Yes sometimes it is better to run electronics cooler but they aren't necessarily more stable at lower temps, actually you want them to run warm for them to be stable. Some electronic ICs come with built in heaters so they can keep them at a warmer temp to gaurantee stablity. It's a bit of a mixed bag really.

**kal** · Posted: Tue Feb 13, 2007 3:30 pm Post subject:

n@t · Joined: 02 Apr 2006 Posts: 63

Hi,

nice Pic Smile

Bernd

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

Hi ...

I have read (with difficult due different language) all topic and I want to change my fans.

The change NMB fans with SilenX IXP-76-18 and IXP-74-14 it's still a good idea?

Thanks

**kal** · Posted: Tue May 26, 2009 7:08 pm Post subject:

Ile · Posted: Tue May 26, 2009 8:32 pm Post subject:

AVphile · Joined: 02 Dec 2008 Posts: 334 Location: Ottawa, Ontario

Is it the convergence tray or the H/V scan boards heating up that causes convergence drift?
I was thinking to replace the 80mm fan with a thicker (greater static pressure) fan. One fellow said there wasn't room for a thicker fan but I don't believe it!
My goal would then be to reduce RPM slightly to reduce noise.

Ile · Posted: Tue Dec 18, 2012 8:54 am Post subject:

AVphile · Joined: 02 Dec 2008 Posts: 334 Location: Ottawa, Ontario

Thanks Ile! You are correct - I'm experiencing whole raster shift but it is not equal for all tubes so they become misconverged. After playing one movie the red shifts away from the green vertically (the most - say 2-3 clicks) and horizontally (less - say 1 click). The blue shifts the least, say 1 click horizontally.

AVphile · Joined: 02 Dec 2008 Posts: 334 Location: Ottawa, Ontario

Ile · Posted: Tue Jan 22, 2013 12:15 pm Post subject:

AVphile · Joined: 02 Dec 2008 Posts: 334 Location: Ottawa, Ontario

Looks like I have "bad" astigmatism on the red. I don't know how to set the rings. Curt said they "don't do much on a Barco" when I inquired.

Ile · Posted: Wed Jan 23, 2013 9:15 am Post subject:

Yes they don't effect that much to focus, but I have found out that bad 2-pole setting can cause drifting.

So especially red 2-pole ring need attention (tab at neck board side), it's also good to check 4-pole at same time.
2-pole ring is used to get even shading for lines and dots. This means how straight electrons hit to phosphorus.
4-pole ring is used to get dots round.

Moving whole tab turns both magnet rings and turning tab rotates those rings to different direction. So probably you need to chance both.

Good Barco procedure for all tubes alignments is at last two page.
http://www.curtpalme.com/docs/BarcoGraphics808s_CRTReplacementProcedure.pdf

Keep in mind that barcos internal patterns dots are square/rectangle (depends about your aspect ratio), so its better to use test patter with round dots from source.

Here's other procedure.
http://www.curtpalme.com/Astig.shtm

Other thing that can help is after astig is done and convergence is done. Set red/blue raster sift to 50/50 from center convergence zone and use vertical deflection and Hsift board pots to center rasters.
http://www.curtpalme.com/Barco808_Layout3.shtm
http://www.curtpalme.com/Barco808_Layout2.shtm

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

I tried to replace the four stock NMB's with four NF-S12A FLX
Stop all noise, absolutely quieter, seems a digital pj :shock :

But after a half hour a "finger test" Smile

I'm back at stock fans: all heatsinks was too warm.

So I'm trying a new approach for my BG1209s
Look the pictures.

Three Noctua NF-S12A FLX instead stock NMB
One internal Noctua NF-S12A FLX that blow air vs opposite Noctua fans (focus, hor. deflection, vert. deflection).
One Silenx IXP-76-18 (120mm - 38mm) that blow air vs opposite Noctua fan (SMPS, G2 board).
Stock NMB for convergence tray.

Today I'll try and will detect warm with my fingers Smile

sorry for language
Suggestions?

**kal** · Posted: Tue Mar 25, 2014 12:14 pm Post subject:

The noise does not come from the fans but from air turbulance. The only way to reduce noise is to air flow speed.
If you put in fans that move air slower, there's less noise, but the projector will (IMHO) get too hot.

There's no way around this other than a hushbox with forced air ventilation.

Kal

Decibel · Joined: 31 May 2007 Posts: 904 Location: Roma - Italia

Here is the result of my test: after half an hour of operation, the focus/shift board was the hottest board.
The SMPS board was very warm.
The boards horizontal and vertical were only lukewarm.
Notes:
- the internal fan no blow air vs focus/shift board
- I'm afraid that the most powerful fan (Silenx) can create a stagnation of hot air in the SMPS board that the weaker fan (Noctua) cannot dissipate.

AVphile · Joined: 02 Dec 2008 Posts: 334 Location: Ottawa, Ontario