Diy Strobe for measuring turntable speed accuracy.

[Steerpike_jhb]

Oh... just a quick 'embarassment disclaimer'! That Kenwood KD29 that you see in the photos of my strobe prototype... don't infer that THAT is my benchmark for vinyl playback! BUT it's light and easy to carry out into good light for photagraphy.

[JaS]

Thanks to Steerpike_Jhb the full plans are now in the library. Enjoy

> DIY Turntable Strobe Instructions <



Regards,
JaS

[Gatto Murr]

If you have some ancient shellacs whose speed differs from 78.26, the Steerpike's flasher can still be used by printing a custom strobe disk.

Go here

http://www.shellac.org/wams/wstrobe1.html

and download "strobo".


regards, Piero

[Audie]

steerpike,

That is a neat strobe you have put together!
It looks similar to the Slate Audio 9volt battery powered strobe that I have. I also have another one which plugs into the Slate Audio "Power House" Power Supply for the Garrard 301.

I have noticed lately that often when I change records on the Garrard 301
I need to readjust the turntable speed a little, after which it is again stable. I guess this means that it is time to remove the platter and clean the platter rim, the idler wheel rim and the pulley.

Audie.

[Steerpike_jhb]

Hi Delcam, Bauzace,
Both of you have suggested 'buying' these goodies, so if the 'market' looks big enough I might make up a small stock to sell - possibly in kit form.
Unfortunately then the ultra low cost isn't so low anymore and distribution may cause difficulties. If you check out the PDF file now in the library, I hope it is all explained well enough for even beginners to get their soldering irons out.

[bauzace50]

Steerpike, this is one important step into accuracy, so, I am definitely interested in obtaining one. Even more so, since there are some tonearm experiments to be done, as suggested by Klaus in another post here. Therefore, every step to promote accuracy is welcome and wanted. If you can get together a complete kit of parts, I would pay for your efforts, parts, design time, packing, logistics, shipping, and whatever you care to include in the mix.
It would be up to the purchaser to learn how to read schematics. I only know how to read pictorials, but can learn schematics, if the motivation is sufficient, such as this item.
Let us know, and thankyou.
bauzace50

[Steerpike_jhb]

There is an error in my schematic within the PDF file!

This is a drawing error - copying from my hand-drawn original, the circuit design & operation are not altered.
The PCB artwork is, and has always been CORRECT.

Pin 8 of the CD4060 must be grounded. Pin 10 should connect ONLY to the two resistors.

I am sending a new update (file date March 08, 2006) for JaS to replace the one in the downloads section. If you downloaded the old one, please ammend yours.

[cjunkk]

Steerpike,
looking at the pdf document, I noticed that in the Parts list C2=22 pF and C3=10 pF, while in the schematic C2=33 pF and C3=22 pF...

Cheers,

Carlo

[Steerpike_jhb]

These capacitors are not at all critical in value. The optimum values also vary depending on the exact wiring layout used, so for instance if you used stripboard, the value would be different to that if you used a printed circuit.
They capacitances do not alter the oscilllation frequency significantly either.

Anything from 15pF up to 47pF works just fine. In most cases you can leave the capacitors out entirely with no ill effects, but as a general rule, I use 27pF for crystal loading capacitors, and the one of them slightly smaller if a trimmer is to be used.

[widman1]

I assembled this strobe and I'm pleased with the results. The instructions were very clear and easy to follow, even for a newb like myself.

I made the PCB by printing a mirror image of the solder-side artwork with a laser printer on glossy photo paper. On my first try I didn't print a mirror image and didn't catch the mistake until I tried to stuff the board and realized everything was backwards. After printing the artwork properly, I taped it to the PCB and used a hot iron to transfer the image to the copper. Then I soaked the PCB in water to remove the paper. It took a couple of tries, but I ended up with a decent image of the traces on the PCB. After a bit of cleanup, I etched the PCB in a standard ferric chloride solution.

I bought most of my parts at Digi-Key. The parts numbers are:

IC1 296-2060-5-ND
IC2 296-2033-5-ND
Q1 2N3906-APCT-ND
XT X013-ND
C2,3 1430PH-ND
C7,8 478-4274-1-ND
C6 565-1929-ND
R1 1.2MQBK-ND
R2 1.5KQBK-ND
R5 56QBK-ND
16-pin socket ED58163-ND
14-pin socket ED58143

I bought the LED, switch and case at a local electronics shop. The LED is rated as 1 candela brightness and works well, even in a brightly lit room.

Thanks for posting this project,
pete

[Steerpike_jhb]

Since the image quality in the PDF instructions didn't come out absolutely wonderfully, I'm making available to JaS two files in Hewlett-Packard PCL-3 format. (lpstrob.prn and lpsmirr.prn = same copper artwork but a mirror image, for those who want to use Press-'n'-Peel)

They work with any HP or other-brand PCL printer from the Laserjet-3 on (maybe earlier ones too, and I think the Deskjets understand PCL as well), and will give the best possible printout quality.
Most importantly, they will print out at exactly the right scale - which is important when trying to get the components to fit into the holes in your finished board.

Once you have the file in Windows, open a DOS window, and use a binary copy command to get it to the printer:
eg (if your printer is on parallel port 1):
c:\> copy /b c:\downloads\lpstrob.prn lpt1:

Sorry - I cannot speak macOs, so you'll have to read the book!
For those with USB printers, here's info on how to copy binary files to them:
http://www.decompile.com/dataflex/tips/usb_printer.htm

[marshaul]

I assembled this strobe and I'm pleased with the results. The instructions were very clear and easy to follow, even for a newb like myself.

I made the PCB by printing a mirror image of the solder-side artwork with a laser printer on glossy photo paper. On my first try I didn't print a mirror image and didn't catch the mistake until I tried to stuff the board and realized everything was backwards. After printing the artwork properly, I taped it to the PCB and used a hot iron to transfer the image to the copper. Then I soaked the PCB in water to remove the paper. It took a couple of tries, but I ended up with a decent image of the traces on the PCB. After a bit of cleanup, I etched the PCB in a standard ferric chloride solution.

I bought most of my parts at Digi-Key. The parts numbers are:

IC1 296-2060-5-ND
IC2 296-2033-5-ND
Q1 2N3906-APCT-ND
XT X013-ND
C2,3 1430PH-ND
C7,8 478-4274-1-ND
C6 565-1929-ND
R1 1.2MQBK-ND
R2 1.5KQBK-ND
R5 56QBK-ND
16-pin socket ED58163-ND
14-pin socket ED58143

I bought the LED, switch and case at a local electronics shop. The LED is rated as 1 candela brightness and works well, even in a brightly lit room.

Thanks for posting this project,
pete

Well, I wanted to buy all this stuff from the same place you did (I figured you did all the work for me! ) but due to minimum quanity requirements the total cost is growing excessively large.

Does anybody have any ideas for where to buy all these components, especially where I can not be subject to minimum quantities?

[arnoldc]

Guys,

I made the VE strobe bt it does not work, as the LED (ultra-bright Blue) seems to be constantly on.

I compared the result with a Sony turntable with a built-in strobe.

Can somebody help?

[marshaul]

I'm not sure that anybody can see a 60hz strobe. I certainly can't!

If you get any light, it probably works, to my thinking. But then I'm new to electronics.

Maybe someone who knows better than I will care to elaborate.