Bigger Boob Tube





Introduction: Bigger Boob Tube

Have an tiny old TV laying around? Why not follow this instructable and create your own personal movie theater with it? Through these simple steps you can project an image of this television screen onto your wall that can be up to 70" across.
1 Small (preferably under 15") TV
1 Mirror at least size of TV screen
1 Cardboard Box of similar dimensions to TV
1 Magnifying Glass
1 Roll of Black Tape (preferably duct tape)

*Optional Materials*
1 Speaker w/ speaker wire

Step 1: Measure Your TV and Locate a Suitable Box

You want to measure the perimeter of the TV, not just the screen. My TV was 10.25 X 11 inches, and my box was 10.75 X 12 inches. You want the TV to snugly fit inside the box, allowing as little light to escape as possible. But don't worry if its not a perfect fit, thats what duct tape is for. The box should be roughly twice as long as the TV because you control the focus of your image by moving the TV back and forth. After you find an ideal position you can shorten the box for spatial issues.

Step 2: *Optional Step*

In this step you will be replacing the internal speaker in your TV with an external one. Don't attempt this if you feel uncomfortable taking things apart. I take no responsibility if you butcher your TV. With that said lets begin. Since your TV is going to be inside a box the sound could become muffled, but if you don't mind this then you may skip this step as it is non-essential. First thing to do make sure your TV is unplugged. I learned the hard way, don't repeat my simpleton mistakes, unless your into the electrical shock thing. Most TVs will have a case that is split into two sections, one part surrounding the front and another part covering the rear. You want to remove the back panel, I've circled the three screw locations on my TV in red. Your TV will most likely be different. Now you should see the innards of your TV. Don't be intimidated by the mess of circuitry and wires, you're only concern is to locate the speaker within the case. There should be a red and white wire running from the back of the speaker, you need to snip it and strip it. Be careful not to cut any other wires, as you can see from the pictures I went a little scissor happy and ended up killing the IR receiver (the blue and white wires), rendering the remote control useless. Now feed the wire you snipped through a hole in the case. Mine had vents on the bottom wide enough to slip the wire through. Now attach the speaker wire to the wire from the TV (red to red, white to white [or black depending on your wire]), and wrap it in electrical tape just to be safe. You don't wanna have to go back into the case because the wire came loose. Good job, now stitch your patient back up. Carefully place the case back onto the TV making sure the screw holes all line up correctly.

Step 3: Preparing the Box

Grab the box that you sized up, and find a box cutter or some kind of knife. First thing to do is cut one end of the box off, real simple. Just make sure not to completely mangle the box. Minor tears are acceptable (lets have a round of applause for duct tape). Now is the tricky part. You must cut a square hole onto the side of the box you want the image to come out of. The cut must be in the correct spot or else you TV image is going to bounce off the mirror and miss the hole. I made my cut 5" from the top edge of the box. This lined up almost perfectly with the 13 X 13" mirror sitting at a 45 degree angle within the box. Don't worry I've included a rough diagram of what you are supposed to be getting at. Make the hole small to start with, you can always make it bigger easily but making it smaller if you cut too big is not so easy. So now you have one end of the box completely open, and one side with a small hole about 5" from the top edge of the box. Now you want to make a space to insert your mirror. Draw a line down both sides of the box at an angle of 45 degrees. You can measure this easily with a protractor... but if you don't have one handy you can take a piece of paper and fold it to make a triangle, carefully matching the edges up. Use this as a guide for drawing your 45 degree line. Now use your knife and cut along the lines you drew. Be sure that these two cuts line up with each other; if the mirror is tilted to one side your image will be distorted. After making the cut take some sandpaper and smooth the cuts over to the mirror will easily slide into place when the time comes. Your box is now ready.

Step 4: Slide Your Mirror Into Place

In this step you will be sliding the mirror into place and sealing up any light leaks with duct tape. I found it surprisingly difficult to get the mirror all the way in the box, sand paper was a huge help. All I can say is don't break your mirror trying to do it. Remember, the mirror should face the open end of the box where the TV will be and the hole we made on the side. Ignore the hole you see in my pictures. Now that the mirror is correctly seated in the box, tape up the sides so it doesn't slide out of place. Now tape your magnifying glass over the hole you cut in the side. Compare your finished box to the one in my pictures. If you look into the open end you should be able to see right out through the magnifying glass.

Step 5: Focus the Image

The downside to this project is the fact that the CRT is not very bright. Most likely you will only be able to see the image at night, or in a room with no windows. You should turn the brightness setting in your TV all the way up. Some CRTs have screen and focus knobs within the case that you can twiddle. Physically moving the TV back and forth through the box can make the most difference, similar to the way you can use a magnifying glass to burn things. If you find just the right spot you will get the best results. If you have a white wall thats the best spot to project the image onto. I have mine set up so it projects directly onto the ceiling, and I lay in bed as I watch TV. I tried to take a picture of the image but it was too dark to be captured correctly. When I tried to up the exposure time the image became blurry to the point where it was pretty much just a square of light on my ceiling. So sorry no pictures :( Well I hope you enjoyed my very first instructable. If you have any improvements, comments, or questions I implore you to post them.



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    I thought you where going to use the Box to make the TV screen bigger not turn it into a projector, it's not a Fresnal it's a Magnifier Sheet. Awesome Idea though I might try it with my Portable B/W TV.

    I did want to say I've took TV's and monitors apart for years and have not ever been shocked. I did however get a shock once from a tube radio touched the wrong tube.

    How about a pic of what the projected image looks like.

    Usually with these type of projection systems the image is not very bright.

    Has anyone tried laying a laptop LCD screen on a Overhead projector. The laptop would have to be next to it and there might be some cabling in the picture but maybe some models are less. Crop it out with cardboard or etc. I know the overhead projectors are expensive units but I picked one up at a second hand store for a few bucks and parted with it before I got this idea.

    1 reply

    Yes, people have done this. I saw a tutorial on it the other day, somewhere. Possibly right here on Instructables. Can't find it right now, the instructables search has gone screwy on me and I can't get actual instuctables ans results. Just peoples collections of "tutorials I'm going to try", basically pictures or other peoples Instructables with no links.
    As for the expense of overhead projectors, seeing as they're obsolete now, I wouldn't be surprised to see prices come down drastically. Especially when people stop buying them.

    Ha Ha! Pointless Step As My TV comes with a Headphone jack! So all I need are some headphones, scissors, and a speaker! (I Know some tvs dont have Headphone jacks But I wanted to say HAHA, And I Did.)

    wouldn't the image be reversed?

    Would you be able to make the projection come out the front of the box? if so, how?

    An idea (I wonder if it would work?): How about adding the arm from an overhead projector over a CRT screen (laid horizontally)? You should be able to scrounge an old overhead projector and an old 14" CRT monitor for nothing. No cardboard or anything -just the arm from the overhead projector epoxied to a CRT monitor. Perhaps also epoxy a few pieces of junk so the CRT monitor will lay stable "on it's back". What's your thoughts?

    This has been around the net forever, I was very surprised when I searched instructables and never found this project. It is typically called a "100 inch tv". I have personally made it. I wonder how this poster's results are because his design is not typical. You need more of the lens exposed b/c the lens is a light collector. So he must have a VERY dim picture. I could be wrong though.

    There is a great thread about it here:

    But here is my own comment from that thread:

    "I just came back to post my results from my experiment with my new ghetto projection tv. To those who say that it is total crap, u must not know what your doing b/c it works. Now let me first say, of course noone "expects too much" from a projection tv made out of cardboard.
    I only wanted to try it out and see what happened. I tore apart an old boombox cardboard box wiht a razor blade, yard stick (barely used it), and some duct tape. i didnt bother painting it. i threw this together in 10 mins. i didnt want to waste time if this thing didnt work. i hooked it to my 13 inch tv, at 3 oclock n the afternoon, 3 windows in the room, shades up (in other words: it was NOT dark). and ta da, i got a pic. i didnt make it huge maybe only like 4 feet or so (bigger than any tv i have), i can see how if u get bigger it might not be sharp unless in perfect darkness. But u ppl who are taping aluminum foil on windows and all that are nuts.

    My rig was pretty crappy, i mean youi could see the light coming ouit of the edges and it still worked! not good enuff to watch but if i cleaned it up i think it will fulfill most ppl's expectations. im gonnna make it nice and out of fiber board probably. i want to build it into a coffee table or something. and yes its true ur screen gets screwy when u turn it upside down, i aint gonna do that , im gonna first get a sharp picture first THAN work wiht mirrors, i know it can be done. i used the very same box and and filled the space with a towel and used it on my 9 inch tv, it was just as good.

    one thing ppl were sayin was , they took the fresnel lens and just held it in front of the tv and it worked better. i can see that may be true. the reason I think is ... is because u kinda jam in the lens (taped to the board) and it bends the lens causeing blur. u definitly need the box itself though , i think just to catch all the light and to stop the light from coming out from behind the lens and shining on the wall.

    2 replies

    if anyone is really interested in building your own projector check out the forum at lumenlab you can build HDTV 1080p projectors if you wanted to. Or just build a cheap one using a psone screen. Here is a actual picture that one of the guys built. Gears of War 1080P!

    my 50 inch LG would be less pixelated but is easily beaten for space and room focus as the LG dominates the room off or on it's masssive and literally partially eclipses the sun in the living room but it heats the room to a nice temperature

    A WORD OF WARNING TO ANYONE WANTING TO MODIFY THEIR TV... Because of the high voltages inside of a TV (which are always there, even when the set has been unplugged for a long time), you should NEVER disassemble a TV unless you are 100% sure of what you are doing. Also, be careful, as there might be some kind of radiation inside of the TV (if you start trying to take the tube apart, which you shouldn't be anyway). Just remember... if you do want to do this, take your time and be careful! Another option would be to connect that speaker to whatever device is providing the input to the TV. if you are using cable TV, then I would recommend using a VCR or something to change channels (and you can use the remote that way), and you can grab your audio off of that. Good Luck everyone, Novice_Geek

    How big is the hole suposed to be that you make in step 2?

    And can you use magnify glasses that are like 3 in diameter?

    Well there is a problem, I tried to take a picture of the image but it was too dark to be captured correctly. When I tried to up the exposure time the image became blurry to the point where it was pretty much just a bright square of light on my ceiling. So sorry no pictures :) (I tried to edit my instructable last night to say this but I guess it didn't save?)

    Did you try using a tripod? I'd really like to build one of these, but I want to know what i'm getting into ;)

    Weis... do some googling you'll find images from these types of builds. But they are difficult to take, they are pretty dim. Read my post above to understand expectations. Its worth messing around with if you dont spend more than $10 on materials.

    Bad plan when you cut even/straight across.You should always stagger your cut 1/4 or half inch away from each other. That way if your insulation falls off you still don't have a short circuit when the wires touch(the metal on one wire is too far away from the other metal).

    hmmm...nicely done. how clear is the picture though i wonder? would a flat screen TV or even and LCD (brighter) monitor make it any better? I've got tons of boxes lieing around and thanks to trebuchet i know that all i need to purchase is a new FRESNAL LENS.haha. great job!