LED "Vacuum" Tubes

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Introduction: LED "Vacuum" Tubes

Vacuum tubes are cool to look at and hot to touch. A nice addition to a steampunk or lighting project, but require a lot of power and break easily.

This project provides a close facsimile that is low voltage, no heat, and more durable. Plus they look cool.

Wear your safety googles and have fun!

Parts:

Candy Tubes (eBay)

Vacuum Tubes (eBay)

LED Tea Lights (Dollar Store)

Step 1: Parts:

Tools Needed:

Goggles / Safety Glasses

Vise

Hobby Saw

Sand paper

X-Acto Knife

Needle Nose Pliers

Small Hammer

Satin or Semi-Gloss Black Spray Paint

Heavy Paper Towel

Wire Cutters

Drill

17/64” Drill Bit

Small Table Vise

2 Part Epoxy

Masking Tape

Optional Tools:

Small Drill Bit

¼” Drill bit

Silver Metal Spray Paint

Small Torch or Equivalent Heat Source

Parts:

Candy Tubes (eBay)

Vacuum Tubes (eBay)

LED Tea Lights (Dollar Store)

Optional Parts:

¼” Plexiglas Rods (eBay)

Color Changing LEDs (found in Halloween novelties, such as little ghosts)

Step 2: Preparing the Insides

Step 1. Preparing The Insides:

1. Wrap the tube in a heavy cloth or paper towel.

2. Lightly hit the tube until you hear it pop.

3. Carefully unwrap the tube. Be careful of the tiny glass shards.

Step 3: Preparing the Insides

1. Holding on to the bottom leads, clip all wires

attached to the bottom.

2. Be careful of the glass; cover area or wear gloves.

3. Cut off the bottom metal plate held on by the tabs shown.

4. With an X-Acto knife, carefully cut out the middle of the mica plate.

5. Insert an LED for size check.

Step 4: Preparing the Base:

. Preparing The Base:

1. You can find these LED Tea Lights at Dollar stores.

2. Remove the battery and pop the bottom off. The “flame” just snaps off.

3. Drill a 17/64” hole in the top of the base.

4. Spray paint the base with either satin or semi-gloss black (flat would work, as well).

5. The base can stay as is. These have and amber color and a slight flickering for realism. If you want, you can go one step farther by getting one of those color changing LEDs out of a Halloween novelty (such as a little ghost).

Step 5: Preparing the Tube

1. Wrap the tube once around

with masking tape, at a desired height for use as a straight line, as well as gripping proposes in the vise. NOTE: Don’t have the vise too tight, you’ll break the tube.

2. Cut along the edge of the masking tape with a hobby saw, turning it as you go.

Step 6: Finishing

1. Using 2 part epoxy, glue the bottom of the tube

innards to the base and let it dry.

2. Insert the LED through the bottom of the base.

3. Apply epoxy to the bottom of the tube.

4. Glue the tube to the base and let it dry.

5. Put the battery and battery cover back on and turn it on.

6. Done.

Step 7: Going Further

To

add a little more realism, here are a few more steps.

1. Drill a small pilot hole in the end of the tube.

2. Then drill the hole out to a quarter inch size. Clean the hole up using an X-Acto knife.

3. Put the quarter inch Plexiglas rod in a vice. While heating the rod with a small torch, slowly bend and twist the rod as it heats up and pull it apart slowly until it gets thinner in the middle pulling it apart it’ll get thin in the middle and then you can break, or cut it off with a pair of diagonal cutters.

4. Sand off the end.

Step 8: Going Further

1. After cutting it down, insert the modified rod into

the tube.

2. Mask off the bottom at a desired height.

3. Using a silver metal spray paint, spray the top of the tube.

4. You can now proceed with step four.

Step 9:

Ok, so I’ve gotten a couple of comments about destroying old vacuum tubes and that they may not be easily obtainable. When I was a kid you could pick up a whole box full for a couple of bucks, but now I realize that they may be needed for antique radio enthusiasts. So, I came up with a fast and easy way to make some tube innards. I would search the internet for pictures and get creative to add on to my design. This is a fast easy basis to build on.

Let’s get started:

Parts Used:

First I looked around for parts that look like what’s in a vacuum tube. I came up with some buss wire (a paper clip would work), some window screening (a finer mesh might look better), 3/8” internal lock washers, and some ½” plexiglass tubing (eBay).

Step 10:

Step 11:

Center the lock washer on one end of the tubing then, using a soldering iron, melt the washer into the end of the tube.

Cut the screen into a ½” wide strip and, using a soldering iron, melt one end into the tube.

Pull the screen around the tube twice, bent the wires down and melted that end in, as well.

Step 12:

Melt some wire into the end and trim, making 3 or 4 wires to keep up off the base.

Cut the tube at the screen line and melt another washer into the other end.

With pliers, bend a piece of wire, as shown, and melt it into the top.

Step 13:

BOOM, there you are. Not perfect, but with some pieces of shiny metal or other small parts glued on you can make this look very real.

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    56 Discussions

    well done. I have been using real tubes and LED's but the results are a bit of a gamble. some tubes are fantastic and show light reflected from the most realistic angles, but others, well lets just say just ordinary. I utilise the vintage radio market and ask the ebay seller if they have any non working tubes for sale, usually they jump at the chance to sell something which usually is just waste. I pay around 50 cents per tube and tell them how I intend to illuminate them, that way they can decide which tubes are most suitable. I will try your way, it seems more creative.

    A clever method of imitating tube internals. One can easily modify it to suit available parts.

    Hi,
    The outside diameter is 1.10 in. / 28 mm
    The inside dia. is 0.803 in. / 20.38 mm
    Jim

    This is a cool idea, but please beware. Some of these old tube are infused with mercury vapor gas which is an extremely toxic nasty gas. Make sure you know what is inside before you crack it open.

    3 replies

    Small receiving tubes use barium getters, which result in that silvery stuff in the top of the tube that turns white when it goes to air. Not toxic, but don't eat it.

    Mercury tubes are industrial types, pretty rare. I had some ignitrons that contained pounds of mercury. Fluorescent lamp tubes contain small amounts.

    I have found mercury tubes in various vintage shops. They are very interesting in their size, shape and design and can be tempting to the unexpecting artist.

    In regard to Barium, it is found in abundance in nature however it can be harmful to humans depending on the exposure they may have.

    People with the greatest risk to barium exposure with additional health effects are those that work with barium. Most of the health risks that they can undergo are caused by breathing in air that contains barium sulphate or barium carbonate.

    Many hazardous waste sites contain certain amounts of barium. People that live near them may be exposed to harmful levels. The exposure will than be caused by breathing dust, eating soil or plants, or drinking water that is polluted with barium. Skin contact may also occur.

    The health effects of barium depend upon the water-solubility of the compounds. Barium compounds that dissolve in water can be harmful to human health. The uptake of continuous amounts of barium that is water-soluble may cause paralyses and in some cases even death.

    Small amounts of water-soluble barium may cause a person to experience breathing difficulties, increased blood pressures, heart rhythm changes, stomach irritation, muscle weakness, changes in nerve reflexes, swelling of brains and liver, kidney and heart damage.

    I don't mean to sound so paranoid but the chemicals used in these devices were never intended to be accessible to humans when they were maid back in the early half of 20th century. I am curious what people are using to power the LEDs. There is a whole other list of dangers when using Lithium cell batteries.

    Yes....it is a nice thing to insert led lights in a tube, but of course care in handling...as Jim says some of them have inside quite dangerous elements (metals)

    Nice work. I like the look of these, but also not a fan of destroying actual vintage tubes.

    Had you thought of simply lighting the vintage tubes with their internal preheat elements, a tube socket and a wall adapter? Guitar players still use tube amps quite a lot, and the tubes they throw out almost always still have their elements intact (which is what gives off that nice glow). Most are 6.3VAC, or two elements in series at 12.6VAC, which are both common wall adapter voltages... neither of which is critical.

    I just gave myself an idea for a related instructable! I'm also thinking it may be possible to drill a tube from underneath and use a small LED inserted into it without completely breaking it.

    6 replies

    Hi, You don't even have to drill the tube, just use a small SMD led with a couple of very thin wires and then just glue the led to the bottom of the tube, you can get a really amazing look without ruining everything, in fact, you can still use the tube because everything is so small there is no problem. Of course it has to deall with the heat. Most tube sockets have a hole in the center anyway. You just insert a 3mm orange or amber led on there and away you go. In fact this is what I did with my hybrid tube headphone amp. It looks amazing at night. I can send you a picture if you want. Cheers :)

    Yep. I found one of my old 12ax7 tubes and a socket for it, as well as an amber 3mm LED, a handful of resistors, some vodka, and an old phone charger. The socket had a pin in the center, but was easy to pull out. Looks amazing lit from the hole in the socket. The vodka was delicious. Now I'm thinking of trying some green, red, or blue LEDs just for grins. I'm going to need more vodka.

    IMGP1232.JPG

    That won't work on most of my tubes. The collar/base of the tubes (type 6L6 or 6V6) are plastic, and can be drilled into the stem, where an LED can be inserted. Actually drilling the glass part of the tubes without breaking them would be extremely difficult.

    Putting an LED into the hole in the tube socket sounds like a good idea for tubes without the plastic stem. Post a picture if you could. Thanks.

    If you drill a hole in it it gets ruined the same way...

    A really intelligent alternative. I think that I can make these now :) :)

    Nice well presented instructable but please don't destroy working tubes
    (but if you are make it the cheap old Russian tubes because there are
    literally warehouses full of them).

    I think this is a great idea to have decorative tubes lighted up.
    To add to the discussion if you search eBay for "dollhouse glass domes" you will find glass tubes that you could use to make it look more real.

    1 reply

    You could also use test tubes. You will have to cut them. Check instructables on how to cut bottles.