Vacuum Tube USB Memory Stick - Quite Impractical But Cool




Introduction: Vacuum Tube USB Memory Stick - Quite Impractical But Cool

About: Software Engineer Musician (Bass Guitar) Maker & Tinkerer

I wanted to give a try to the "conversion" of an old vacuum tube into a glowing USB Memory stick.

Though impractical, I find it cool and a nice accessory to start conversations at the local hackerspace.


Here's what's needed:

  • An old Vacuum tube, preferably a small one.
  • A slim USB drive. The key-shaped Jaster ones are great since they are cheap and have activty led solder pads available.
  • A 220 Ohms resistor
  • An ultra bright red led (I've used a scavenged RGB Led, using only the red one).
  • A bright yellow led
  • A bit of very thin copper wire
  • A 3D printer for the base
  • A bit of 1mm brass wire

Step 1: Print the Base and Bottom Cover

Print the base and bottom cover.

You may need to adjust the model size to your actual tube size.

Step 2: Open the USB Drive and Cut It to Shape

Open the USB drive using a sharp "opener tool". The two sides are stuck together.

Use a dremmel with a cutting disk to cut the USB drive to fit in the base.

Step 3: Solder the Yellow Led

The yellow Led is soldered on the 2 solder pads located at the end of the USB drive, with the right polarity.

This is an activity led that blinks (turns off) when data is being transfered, and is on when no data is being transfered.

Take care, these pads are very fragile and break very easily (I broke 2 of them).

So first cut and bend the led leads so that it fits in the base, a little below the tube's bottom.

I stuck the led to the USB drive and then soldered a bit of thin copper wire between the solder pads and the Led leads.

Plug the drive in and check that the LED works as expected.

Step 4: Solder the Red Led

Solder the red led.

Here again I've shaped the led leads and stuck the LED onto the USB drive using a bit of hot glue.

Connect the anode to USB +5V via a 220 Ohms resistor, and connect the cathode to GND.

It's safe to test that the leds are working as expected before assembling the base.

Step 5: Assemble the Base

The assembly of the base is straightforward.

The usb drive is suck on the bottom cover using super-glue.

The tube is then stuck on the base using super-glue

Step 6: Add the Brass Harness

I wanted to give it some kind of steam-punk look, as well as protect the tube from shocks, to I bent a bit of 1mm brass wire to shape and stuck it in place using a bit of super-glue.

I had to drill the holes in the base using a 1.2mm bit since 3d printing was not accurate enough for these small holes.

Step 7: Enjoy

1 Person Made This Project!


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26 days ago

So clever, using LEDs to make it appear that the tube is glowing. So funny... I just had to make it!


3 months ago on Step 7

Rather than using LEDs, why not drive the valve filament from the USB supply? Mullard valve types beginning with E and with 80- or 90-series numbers (e.g. ECC81) require 6.3V and should glow nicely, if not very brightly, driven from 5V from the USB socket. What's more, they will get reassuringly warm - great on a cold winter's day! Alternatively, Mullard types beginning with D (e.g. DL94) require 1.4V or for some, 2.8V so would require a series resistor, but have an exposed filament. Details of all those are in the Mullard Data Book which you should be able to find online. I got the 1956/66 edition from somewhere a few years ago, having thrown out my original many moons ago.


Reply 3 months ago

Kind of like you said, they get warm....and sometimes hot. Although a great asthetic, probably not very safe.
Is there a way to vary the led output according to the amount of data being transferred IO to the memory chip? Sandisk does this with theirs. Kinda cool.


Reply 3 months ago

Valves can get quite hot with 300V on the anode, but not just from the heat of the filament. I just happen to have an EZ80 to hand which takes 600mA at 6.3V. Running it off 5V, after 10 or 15 minutes the glass is only a little too hot to touch comfotably and nothing like hot enough to cause a burn, however the glow is a bit disappointing. Apart from power output valves such as EL84, most other miniature all-glass valves only take 300mA filament current so they certainly wouldn't get uncomfortably hot. It'd be worth selecting one where the silvering in the top (the getter) doesn't obscure the top of the filament and where the anode is sufficiently wide so as not to obscure the cathode too much.

As to your other question, some USB sticks have a LED which lights when you access it, and those that don't, when you get inside you may well find two pads at the end for a LED. You could connect your red LED to these and the yellow through the resistor to the USB 5V and ground. This may be what Patrice has done - he doesn't make it very clear.


Reply 3 months ago

Indeed that's what I did. I will make it clearer and indicate the polarity.
The yellow led is the activity led. It blinks when data is being transfered, and is on when no data is being transfered.

I actually took an old tube scavenged from an old radio. I don't have any other small one left. Having one with a smaller "getter" would have been better indeed.

As for powering the filamend, I didn't want it to draw too much current and at 5v, it would have been quite dim I think. That's why I chose to use a red led instead.


3 months ago

I must admit, this is a REALLY KOOL project!!


3 months ago

Yea, LOL, when I first saw this, that was my exact thought.(how is he getting the filament to light??!!) Along with, how did he drill a hole in the bottom of the tube????????, after I saw the parts list........