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Strobe Disk Light Source

oldvinyldude

oldvinyldude

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I own a few turntables which lack a strobe to confirm speed accuracy. I printed out a free strobe disk for 33 and 45rpm speeds from Vinylengine, but lack an effective light source to use it.

There are purpose built strobe light\strobe disk set available, but for such an occasional use, they seemed like overkill.

I read through several suggestions here, for a light source. I tried the following: Small LED flashlight, a fluorescent table lamp, a halogen desk lamp, my cell phone flashlight, and an old style (tungsten bulb) nightlight (that use a C7 clear bulb). None provided enough contrast to see reliably, the bars of the strobe disk. Indeed, only the halogen reading lamp gave me any useable contrast to see the bars.

After a bit of research, I decided I needed a neon light source. I tried in vain, to find one that was definitely neon, and in such a physical package to aim at the strobe disk conveniently.

After some more research, I have ordered some neon lamps, and 100k ohm resistors, to make my own light. I have some small clear plastic tubes which I hope will be a good size, to safely contain the lamp, it's resistor and the soldered splices to a lamp cord.

I will post back, once I have tried this setup. I hope it works, and I will then post some pics, and details of the parts needed.

Wish me luck!
 
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And what will be the power source? You need 60 cycle in the light to see the strobe effect. I have a fluorescent trouble light that has a magnetic ballast to run a twin tube fluorescent lamp. Works great. Some LEDs will work, but they are the ones with poor power supplies and strobe like hell (not a good thing for home lighting).
 
I will use lamp cord, soldered onto the resistor\bulb assembly, plugged into the wall outlet. I don't have an old style florescent light (with ballast). No LED light source I had lying about would work.
 
vwestlife said:
Get a cheap LED bulb from the dollar store. You know, the ones which feel as light as a ping-pong ball. They all flicker at the AC line frequency (60 Hz in North America).
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This works. I even found one that would plug into the socket on a Technics Sl-1100a and it worked well. You can also just plug it into a basic extension cord.
 
Nothing to do with brightness, its just the frequency. Strobe discs require accurate 60 or 50hz, and if the cell doesn't flash at that rate it won't work. Used in flashlight mode its just "on".
 
oldvinyldude said:
I own a few turntables which lack a strobe to confirm speed accuracy. I printed out a free strobe disk for 33 and 45rpm speeds from Vinylengine, but lack an effective light source to use it.

There are purpose built strobe light\strobe disk set available, but for such an occasional use, they seemed like overkill.

I read through several suggestions here, for a light source. I tried the following: Small LED flashlight, a fluorescent table lamp, a halogen desk lamp, my cell phone flashlight, and an old style (tungsten bulb) nightlight (that use a C7 clear bulb). None provided enough contrast to see reliably, the bars of the strobe disk. Indeed, only the halogen reading lamp gave me any useable contrast to see the bars.

After a bit of research, I decided I needed a neon light source. I tried in vain, to find one that was definitely neon, and in such a physical package to aim at the strobe disk conveniently.

After some more research, I have ordered some neon lamps, and 100k ohm resistors, to make my own light. I have some small clear plastic tubes which I hope will be a good size, to safely contain the lamp, it's resistor and the soldered splices to a lamp cord.

I will post back, once I have tried this setup. I hope it works, and I will then post some pics, and details of the parts needed.

Wish me luck!
Click to expand...
Kind of laughing at myself... use an old fashioned fluorescent desk lamp, the irradiating type, and it will bring it forward in high definition, something without an internal power supply. Most LED affairs are rectified and filtered to remove the very thing you need. Neon across the power line with proper resistors work great too, you might use a little transformer between the power line and the neon lamp resistors for a bit of isolation.... don't rectify it. Many tables used neon across the line through a resistor, thinking Dual. You need the proper line frequency for the disk which shouldn't be a problem... 50 or 60 hz.
 
gadget73 said:
Nothing to do with brightness, its just the frequency. Strobe discs require accurate 60 or 50hz, and if the cell doesn't flash at that rate it won't work. Used in flashlight mode its just "on".
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There are cell phone apps that will fire the camera’s strobe at a user defined frequency.
 
vwestlife said:
I tried a strobe app on my phone and it tops out at 47 Hz.
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This is what I found as well.

I also went looking for the below at the HW store. I could not find one-just the plug in and observe the status lights type. Guess the one with probes is too dangerous-lol

Coolhandjjl said:
These pocket 120VAC neon test lights work too. Since they’re neon, they flicker at 60Hz.
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When you're taking down your holiday decorations, grab a string of LED Christmas lights and you can use that! Many of them flicker violently because they don't use any filtering at all, they just drive raw rectified AC straight into the LEDs.
 
Strobily App for Android includes user-definable frequency. There are several other apps that will do the same. As for its accuracy, why not give it a try and see? It's a free app after all.
 
DavidTT said:
Strobily App for Android includes user-definable frequency. There are several other apps that will do the same. As for its accuracy, why not give it a try and see? It's a free app after all.
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the trick is how do you determine if its the strobe or the table running at the wrong speed?

I don't mean to sound like a smartass here, just I've been down the path of trying to figure out which of two possibly variable things is wrong without being able to rule out either. It really doesn't work.
 
Maybe it's wrong of me but I would trust a highly-rated app to strobe the phone light at the correct frequency. It's not that complex and these apps have been out there a long time. This is not something that depends on accelerometers.
 
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