Hi, I'm going to show you how to make a tiny TV/Oscilloscope. You will be working with a Cathode Ray tube which requires high volts and high pressure vacuums, so be careful. To build this you need patience.

Please rate my instructable or leave questions. They will be answered.

This is an old instructable I accidentally deleted a while ago and managed to find via a link deep in the interwebs. The TV has since been lost, but I plan on making a new and better one.

Step 1: Get All the Stuff

You will need...

+ A soldering Iron/Gun*
+ Solder*
+ A small phillips screwdriver*
+ A Hot Melt glue gun
+ Hot Melt Glue
+ Scissors

Electronic Items:
+ 3 DPDT switches*
+ Reasonably thin wire*
+ Two nine-volt battery snaps*
+ A Relay*
+ An LM386 audio amplifier IC*
+ A 100k Potentiometer*
+ A 10uf Capacitor*
+ A Small Speaker*
+ Female AV Jacks°

Other Items:
+ An old video camera {circa 1990}
+ A craft box to build it in

*can be bought at radioshack etc.

Step 2: What Are These Dohickys?

Before you get started, you will have to take apart the viewfinder/microphone. Pretty fun actually. Pictures are here to help.

Step 3: Get Out the Important Part

Take out the video section of the viewfinder. Don't break any wires or anything and be very careful not to get shocked. Capacitors inside may still hold a small charge. Also, don't break the screen for christ's sake.

Step 4: Identify the Connections

This is frustrating. You have to figure out what is power in and video in. Hook up a nine volt to random wires to find out. If the screen lights up, you have found the power input. Once that is found, add more wires until some garbage appears on the screen, that's video in. Mine came out like this...

Step 5: Build and Connect

Have fun. Think, Cut, Solder, Sweat, Get Burned, Yell F*ck, Stomp around, Rest, Build, Freak out when it don't work, Cry, Scream, Pee, Wash Hands, Build, Get it Done, Then realize you forgot batteries.

A pictorial of the layout is below. The wires are obviously not 'connected' to the batteries, the 9v battery snap however, you get the idea.

+ On the LM386, the side with the indentation is top. Very important.
+ The colors of your coil wires may be different. It is trial and error. Go to http://censtron.com/?p=18 for more information on coil hookup.
+ Taping wires down makes it easier to move around.

Step 6: Mount

Get the glue gun ready and build a thingamabob out of the craft box to make it look nice. It also may be a good idea to cut a hole for the screen...

<p>That's pretty sweet! i love those little CRT's. a few month's back i made a Mini CRT Pong game and its a two player (if you don't mind smashing faces together to try and see the screen) :)</p>
<p>I obtained one of these (20mm) from a Canon Digital8 tape camcorder recently, and a few others over the years, IF you do this, be warned, many of these take more than one input type and voltages, 5v for digital parts, 12v for small flyback+H/V Coils.</p><p>Also, most camcorders from the 80's or 90's have an onscreen display generator (batt, tape time, status, etc..) some have them in the viewfinder as was the case for my Canon E708, its viewfinder drive board contains a character generator chip, and takes 8N1 ASCII serial data input 1200bps.</p><p>I plan to use two of them for my quadcopters FPV video, the OSD generator in the unit will be connected to an Arduino unit that recieves my telemetry signals, then displays them onscreen</p>
<p>Neato! I've never thought that there might be a mini composite CRT in old cameras like this! I've seen plenty in thrift stores and passed them up as &quot;worthless junk&quot;, but knowing this...</p>
<p>Awesome!</p><p>I just made one and it work's pretty well! :)</p><p>Thanks for the information!</p>
I like this.<br> <br> I never thought of that as a source of a cathode tub.<br> <br> Have you seen my Instructable, Building a Digital Oscilloscope from a DIY Kit?<br> <br> <a href="https://www.instructables.com/id/Building-a-Digital-Oscilloscope-from-a-DIY-Kit/" rel="nofollow">https://www.instructables.com/id/Building-a-Digital-Oscilloscope-from-a-DIY-Kit/</a>
this rocks <br>
Wow! I'm pretty sure I found an old video camera just like that in a thrift store.
100k pot for the gain adjust on your LM386, are you sure?! do you mean 1k?
I apologize for my rudeness... I should have been a little more thoughtful with my remarks. and hey, im starting to spell bad too. Sorry.
No problem, I used to use IE back then. IE had and still does not have a spellcheck.
pleeeeeeeeeeease learn to spell. it really is annoying. thanks<br />
Forgive me, but&nbsp;part of spelling is capitalization. Good job with the punctuation, though.<br /> <br /> It's so funny when people post indecipherable garbage. It really reflects their personality.
i took apart a camcorder and found a crt with a 16mm screen and 6 pin base + a psu (2,200v) as well.<br /> for brightness try adjusting the trimpots <br /> e.g. those blue things with a screwdriver.<br />
try putting a 4.7-10 uf cap on the output of regulator&nbsp; (mightprevent/reduce picture shrinkage)<br />
&nbsp;hey can u take a picture of the board where ur power wires and video wires connect to the tv board. i cant find the wires.
Unbelievable.....a KID of 13yrs has SO much electronic savvy, so much vocabulary, so many tricks???? ...have seen many child prodigies and have mentored some myself, but this guy beats them all !! Either he's a miracle or a well planned hoax. Wish it isn't the later though...... I wish him good luck and Gods very best!!!! PS: wish there are ( I'm sure there are ) more kids like him around, too!
i think the fact that because you don't want to take pictures, just takes the instructable down on so many levels. i mean it is quite original, and heck, i probably wouldn't be able to make it. but if you have the means to, and the time (it would be quicker to take a picture and draw-on or even use the box feature on instructables, than to draw it by hand) i think that the final result of would of been much more professional.<br/><br/><hr/><br/>On a second note, this is from a point of view of me trying to figure out how this was built, im just going to say that i am having a hard time following instructions, such as in step 5, i have no idea what i am connection, to where, and from where.<br/>
Hey latobada! I agree with you about the lack of photos, it's kinda hard to figure out whats going on. Basically this hack is not really a mini TV hack at all, its a mini video monitor hack. These old camera viewfinders are simply tiny video monitors that will display a composite video signal (the kind you get out of a DVD player, VCR, or the side of a video camera). They are normally constructed with three wires leading into them, a positive power lead, a common ground, and a positive video lead. All you have to do is figure out which leads are which through trial and error, then hook the positive power lead, and the common ground (the negative lead) to a power source, and then hook up a video source to the positive video lead, and also the common ground lead, and you should get some sort of image on the screen. Also, in step 4 of this instructable, Googfan recommends hooking up a 9v battery to test the leads, this might not be a good idea as in my experience these monitors seem to run on 3v-6v, but you can find out for sure by taking a reading off the original camera output. If the video appears fuzzy or dim, you can normally adjust it by turning the mini POTs the should be somewhere on the driver board, on Googfan's step 6 they are the two little blue things just under the screen. Anyway, here are some photos of an old effort of mine, running off an old motorola phone charger, and displaying the output from my DVD player.
dude! i have almost the same CRT viewfinder and i cant get it to work, can you contact me about which cables and etc etc.!!?!?! PLEASE!
Hi, I've also got a b&w crt viewfinder in my misc. box of stuff and I'd like to use it as a video monitor. It came out of a Sony CCD-F70 camcorder and has 4 leads. How do you figure out which wire is which through trial-and-error? Thanks.
srry bout the delay, hook random leads to random battery leads, things should happen. btw, my instructabe got updated
I already bult the tv and did not want to re-take it apart to take pics
you could of done zoom-ins
also the step 5, you need a knowlage of circuit schematics.
how would you make this just a tv and no oscilloscope?
i done that it shows just static.....damn : (
will it work if you use an old but working 5inch tv(12v version) and connect the four magnet wires to an oscillator (horizontal) and vertical to what you want?
also use a transformer with an isolated output for each circuit instead of two or even three batteries use a single 6or 12v input instead feel free to ask for a wiring diagram to make the power supply.
that wouldn't work because when one coil draws current, the magnetic field is weakened, affecting the other coil. They would attenuate eachother.
they are voltage regulated and the transformer is twice rated for the current and higher current will not mean less voltage.
Yes it would. Ive tried it but i did not have a variable oscillator. (what we do w/ the portible tvs now? they dont work)
Hey, I have really wierd geckos who will sit at the end of their cages watching tv, when i let them roam around on my bed or floor they just stop and stare at the televison, i leave it on when i go to school because they seem to appreciate the company =D<br/><br/>But i've been thinking about making a miniature television screen that i could plug into my little movie box so that my geckos can watch stuff on it (they seem to really enjoy watching movies i have on my ipod)<br/><br/>How will i do this?<br/>
Interesting. what species are they? Well first you would have to build this mini tv, tnen you simply connect the "video in" to a vcr/dvd thing.
Leopard Geckos, Well, leopard gecko now, one died *cries* nine years old<br/>Anyways what im asking is how would i construct this?<br/>
The instructions on how to make the tv are in the instructable!
what are the details on the 10uf capacitor?What kind of Relay? where can I get the 2m potentiometer meter?
Ah so there was an instructable for a crt oscilliscope i suppose mine is moderelty diffrent though (have a look(go ahead(i dare you))) Why use such a small screen though why not perhapse use a small tv (my instructable)
That's the point. This is an ins. for a TINY teleision that, w/ a flick of a switch, can be turned into an o-scope
Didn't really zone in on the tv part interesting I suppose it would be cool if you got 2 of those viewfinders and made a headmounted display maybe hook it up to well I don't know something. maybe one of these days ill get my hands on one of those
Tried. But ended up blowing out one. Gave up because old cameras are hard to come by.
Im gonna try it, or a single one you hold up to your eye
I did do that once but it got boring after a wihle. Check out my website. I made it into a nightvision helmet. www.mrgoogfan.co.cc
FCK forgot to spellcheck
Can you help me? I tried to wire this up, but when I applied power, I saw smoke. I was using the 5V leads from a modified computer PSU. I have two boards. One of them lit up for a second, popped, and stopped. The HV power supply still works because I can hear the high frequency noise, but the second boards is quiet...
may I ask how big it is? i really cant tell by the picuer you shown.
pictures about the size of a penny
Wow thats small =D<br/>
Say, I have at least three old oscilloscopes lying around (including a ancient Philips dual-trace, with a massive 3" round screen). The hooking them up to the stereo, and the holding a magnet near the screen, tricks have gotten a little stale. I would very much like to watch TV on them. Any ideas on how to accomplish this?
im sorry but no. oscilliscope tubes are not designed for picture. + the phosphor is too slow + there is [usually] no brightness pin on the tube + most are electrostatic rather than magnetic deflection. Youre better off buyng a new tv than trying to turn an oscilliscope into a tv.

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Bio: Physicist
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