How do you level your turntable?


Short of buying a 400 dollar digital level, what have you found that really does the trick. I've tried various cheap bubble levels with fair to poor results.
rloggie
Great input really got me thinking. I had forgotten that the spindle of my turntable is removable. With it out I was able to put the bullseye bubble level directly in the center of the platter. That gave me a reasonably good reading. Guess I'm headed to Sears now.
I use a cheap, 1" long bubble level (not a round one, which would be pretty useless).

To compensate for the inaccuracies of a bubble level, if any, all you have to do is spin it 180 degrees and re-check on the same axis. If the results differ, halve the difference and you're level. Nothing could be simpler.
I picking up a pair of cables at a fellow A'goner's house a couple of weeks ago and he showed me an interesting experiment relating to bubble levels. He showed me 4 bubble levels on the same surface, each of which had a different reading. He explained that these are all hand calibrated using some sort of photographic device, which explains for the discrepancies between the bubble levels. He said he uses a digital level for his turntable, which is the best way to achieve a perfectly leveled table. FWIW, he's an architect and an engineering professor at a major university.

Me, I use a bubble level because I'm feeling cheap.
Dougdeacon has the answer to this. I have $500- worth of levels to install fine cabinetry and I always rotate 180 degrees and halve to find dead nuts. The ONLY way to find true level with a bubble.