Mini TV / Oscilloscope




About: Physicist

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 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...



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    176 Discussions


    2 years ago

    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) :)


    2 years ago

    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.

    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.

    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


    2 years ago

    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 "worthless junk", but knowing this...


    4 years ago on Introduction


    I just made one and it work's pretty well! :)

    Thanks for the information!


    7 years ago on Step 2

    Wow! I'm pretty sure I found an old video camera just like that in a thrift store.


    8 years ago on Step 5

    100k pot for the gain adjust on your LM386, are you sure?! do you mean 1k?


    8 years ago on Introduction

    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.

    1 reply

    Reply 8 years ago on Introduction

    No problem, I used to use IE back then. IE had and still does not have a spellcheck.

    El Manokikazz

    Reply 9 years ago on Introduction

    Forgive me, but part of spelling is capitalization. Good job with the punctuation, though.

    It's so funny when people post indecipherable garbage. It really reflects their personality.


    9 years ago on Introduction

    i took apart a camcorder and found a crt with a 16mm screen and 6 pin base + a psu (2,200v) as well.
    for brightness try adjusting the trimpots
    e.g. those blue things with a screwdriver.

    1 reply

    Reply 9 years ago on Introduction

    try putting a 4.7-10 uf cap on the output of regulator  (mightprevent/reduce picture shrinkage)


    9 years ago on Step 4

     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.

    dark sponge

    10 years ago on Introduction

    You could use 6 rechargeable AA batteries. It would last longer and would supply enough power for the sound and the picture at the same time.

    2 replies