Keohi HDTV - Learn About - General Tips - Black Level

[LEARN ABOUT][GENERAL TIPS][BLACK LEVEL]

Duvetyne

Tip by Dave Gibbons on Preparing Duveytyne:

Perhaps someone has posted this somewhere, but folks who use Duvtyn cloth to darken the interior of thier RPTV's should be sure to raise the "nap" on the Duvtyn before they install it. You can wash the Duvtyn (probably eliminating the fireproofing, if you bought fireproofed Duvtyn) or you can gently brush up the nap until the Duvtyn looks uniformly dark.

The fuzzy side of the Duvtyn cloth is compressed very flat as manufactured, and unless you raise up that fuzzy surface, the light-drinking ability of the cloth just won't be there.

Vacuum the cloth well after the brushing to eliminate loosened fibers, and touch up again once installed with brush and vacuum for maximum darkening effect. (I covered the gun lenses with safety caps before starting any of this, and only removed them after the entire interior of the cabinet was vacuumed, and the mirror blown clean with compressed dry gas)

Tip by Paul Hives: "Adding Duvetyne to the inside of my TW56x81 wasn't very difficult.

Materials and tools required:

4 yds Duvey. Maybe a little more in case a piece is miss cut.
48" Straight edge
Sharp scissors or knife (I used scissors)
Crayon, grease pencil, chalk any one will do
Large flat table (I used my ping pong table).
Tape measure.
Staple gun with ¼" staples.
Black paint pen.

Ok then. First remove the screen from the TV. To do this, remove the
grill covers on the lower corners of the cabinet. Reach in on the bottom until you feel what amounts to a grip hole. Grab firmly and pull hard.

The velcro that holds them on is very good. Feels like you're breaking them but not. Just pull hard. Two screwed tabs hold the bottom of the screen assembly to the cabinet. Remove the screws. Now grab the side of the assembly, pull out the bottom about an inch and then raise the whole assembly. Set aside.

With the Duvey flat on the table, felt side down we'll measure the pieces we need. I used the following order:

Two vertical sides

Two sides next to the mirror in the back

Strips for the frame that holds the screen

Strip for the area above the mirror

Two lower sides next to the CRT cavity

Area behind the CRT cavity

Area below the mirror

Top

CRT cavity. (See info on cleaning optics before doing this step)

Since a lot of the pieces are opposites, measure and cut one and then flip it over to cut an opposite one. To mark the material I used on of my sons yellow crayolas. Worked great. The back of the material is stiff and easy to mark on.

Generally speaking a started by stapling one corner and then working my way around the other corners. I tried to use the minimum amount of staples that would hold the material securely. Since the stuff isn't moving, in some cases just a couple of staples along the top and a couple along the bottom will do the trick.

When measuring the pieces allow some extra to go around the mounting blocks inside the TV. Just staple the material around them. Since the stuff is pretty stiff it's real easy to hold in place.

For the most part this should all be fairly self explanatory. The only part that was a little trickier was the cover for the CRT cavity. I started with newspaper. Cut a rectangle about an inch larger all around than the size the cavity. I then layed in the paper and carefully traced the CRT with a felt marker onto the paper. I cut out the circle and test fit the paper. Once satisfied I transferred it to the Duvey. To put this piece in what I did was staple the material to the front edge first. As your kneeling in front of the TV this would be the area closest to you. Then I slid the holes over the CRT's. Holding the far end of the material, you can actually stretch it a bit, I stapled the back end. Doing so made the material tight. The extra inch or so from the cut is enough to hold it and stretch it. I did the same thing to the sides. Simply stapling to the sides as a went. When I was done it looked kind of like a flat tent cover with holes trough which the CRT's stuck out of.

After all the stapling was done I used the black paint pen to dab the staples. At this point just about every area that was wood now has material on it. It is impossible to cover every last millimeter but it can be quite close.

It was already feeling darker in there. It seemed that the light I was using wasn't putting out as much light. I knew it had to do with not having reflections off the painted interior surfaces.

One more thing. Clean the mirror and optics before closing up. I used a soft cotton rag. An old washed t-shirt always works for me. No chemicals or water or anything like that. Just waded up a little and gently run over the mirror and CRT. You'll be amazed at how much dust and lint is picked up.

BTW. Shine the light into the CRT's. If you see what appear to be little reflections then there is dust in there also. Easily fixed. Purchase or borrow if you don't have one a photographers lens blow brush. It is a brush that is attached to a squeeze ball. You can squeeze air at the same time as you brush. As an alternative you can also use the air in can that electronics repair people use. The air can may be purchased at places like Radio Shack. The brush at photography shops. I have seen them in the photo dept of K-mart and Wal-Mart.

Ok then. There are four screws holding the CRT in place. Remove them and lift the CRT straight up and set it aside. Make note of the position. It will only go back in one way. BTW. This does not alter the focus setting. That piece all comes out with the CRT's. At this point there will be a lens exposed. It is on this lens that you'll see the offending lint and particles. Blow them or brush them off. Repeat this for all 3 CRT's.

Put screen back on the TV and enjoy. The blacks are better and the colors appear richer. This also results in a sharper image. Mind you this is without making any other changes. I checked my convergence and it had not changed.

The whole process took about two hours."

Install Tips from Tom Herman

"Duvetyne comes in various grades. Preferred is "Duvetyne FP", which is heavy & stiff, making it much easier to handle & install. It costs about $6.50 per linear yard (width is 54").

Duvetyne is much less light reflecting than ordinary black velvet. If your TV's already been done with black velvet or velour, I doubt the incremental benefit of Duvetyne would be worth it, but if you're starting from scratch, by all means go with Duvetyne. The heavier grades of Duvetyne are sometimes also called "commando cloth". Inside a cabinet I doubt floating cloth particles would be a problem; you have to whack the cloth to get it to release loose particles. I guess you could "pre-whack" it before installing, if concerned ...

On my Tosh TP61 I used up about 4 yards because of several goof ups I made...I was VERY glad I had ordered a full 5 yds. I used 3M brand spray adhesive #77 to glue it to teh cabinet, which was kind of a pain & a bit messy. If I were to do it over, I'd staple the Duvetyne, and paint the staple heads black with a marker.

Additionally, I strongly urge you to keep some acetone solvent nearby. As careful as I was, I got some adhesive on the corner of my mirror, but acetone removed the 3M adhesive.

Since nail polish remover is mostly acetone, that might do in a pinch.

And to protect the CRT lenses from errant goo, put something loosely over the lenses & CRTs to protect it (eg aluminum foil or plastic wrap). "

Additional info: Commando cloth is the 16-oz Duvatyne variety. The Heavy weight Duvatyne is 12-oz, and the lightweight version is 8-oz.