Here is a very nice turntable strobe generator program that runs under Windows operating system. It will produce a strobe drawing of any speed at 60 or 50 cycles. I found it a few years ago while surfing the WEB, I can't give the author credit as there is no name listed in the program.

I usually print it out and then glue it to an old 10" record.
Below is a sample output, to download the program click on the picture.
For those squeamish about downloading executable files - this program has been checked for viruses and is clean.

STROBE.EXE