tachometer to measure TT speed

[kffern]

Hi,
I just bought a digital tachometer off ebay http://cgi.ebay.com.au/New-Digital-P...rkparms=66%3A2|65%3A1|39%3A1|240%3A1318#ebayphotohosting

Something nearly the same sells at Jaycar for A$80.

Anyway I was wondering if anyone else uses it to check TT speed.
I checked my Technodec at it was dead on 33.3. Then my Lenco L75 which I thought was correct but was actually 33.5.
Surprisingly a Thorens 126 III was the most steady with steady 33.3 for over a minute where as the other 2 would occasionally go to 33.4 for one reading in a minute or so. Maybe my hand was shaky - a tripod would help.

It seems to be pretty accurate but I'd like to know what others think.

Kffern

[Citation16]

I looked at the item you bought on EBAy

the speed acuracy is printed as follows: Accuracy: +/- (0.05% +1 digit).

I am using an Oracle strobe I glued under the platter of my Oracle and that I can see with a mirror and a light while I play a record.

The strobe has some 230 or so marks for the 33 1/3 speed.

If the speed changes by one mark for one turn, its a .0043% variance.

Now, I can get the speed ajusted to a drift of 1/4 of a mark per revolution - this equals .0010869 or about 1/10 of 1% speed variance.

Thus, I prefer the strobe, since it appears to give me more information and precise speed measurement.

[Nanook]

good to .1 RPM +/- .05 RPM close enough for me and not such a PITA as the Oracle calibrator (I own an old Alex). quickest, high precision measurement I could do...,

but if you set it to the nigh RPM range it will provide more precise measurements...