TT speed

The .11Hz change in pitch is WAY off the mark--that was calculated by looking at the angular difference at its extreme, which are many minutes apart, then calculating what this angular change means in terms of pitch.  But, say the recording is of a 1,000 hz signal, at any point along the record, it is playing a 1,000 hz signal, which is what you would hear no matter where on the record, you are playing.  To the extent the very tiny movement forward or backwards from the movement of the tonearm along an arced path changes pitch, it is extraordinarily small, and the amount of movement is dependent on the time frame one uses to measure the change.  If one measures say a two second interval, there will be an extremely small change in position relative to the starting position, which, I suppose, could represent a theoretical pitch change; a one second interval would then be about half as much of a change, and .5 sec, half again (kind of a Zeno's paradox).  The instantaneous pitch (if there can ever be such) would respresent a point with no change at all.

The fallacy of comparing the two extreme points on the record and calculating the difference as a change in pitch, is somewhat like the following analogy:  Suppose I have a fifteen foot long car.  If I move it ten feet forward, what I have after the move is a fifteen foot car whose location is 10 feet different from where it originally was located.  It is not a stretched out 25 foot car covering the interval of its movement (again a problem Zeno grappled with).  

Personally I would not use an FFT for fine measurements.

A better method would be shift the 1kHz down to DC and then plot the phase as a function of time.

The width of the FFT bins will mate it appear like it is one frequency, but it will be a chirp in frequency,. And with any spindle hole offset, it will be a chirp with with a sine wave riding on top of it.

There will no now way to get the sample rate high enough to have the FFT size be high enough to get any sub Hz resolution.
And with the chirp and sinewave it will be smeared within the bin to all buggery.

Holmz, if you are thinking of how to prove or disprove your frequency hypothesis, I fear we cannot do the experiment in the real world, because we require a perfectly created, perfectly centered, and perfectly flat LP on a TT with perfect speed accuracy, in order to examine the phenomenon you claim exists (and others do too, in fairness). Imperfections in any of the foregoing elements would likely cause a frequency distortion that would drown out the effect you want to detect. Fourier or no Fourier. But we can argue until the cows come home.

By the way, I was thinking that your observation, that you have to rotate the platter by about 20 degrees in order to set the two null points using your protractor, is really a product of how your particular protractor was made. It is possible to imagine another protractor where the cartridge can be aligned at the inner and outer null points without having to rotate the platter at all.

@lewm I agree it is somewhat meaningless in term of the platter speed and W&F levels…

But ignore the protractor and just draw a radial spoke on the paper. And there too… as the stylus moves inwards walk in “platter rotation space”… (well all except a linear tracker)

We do not need to do an experiment, as we can do it all solely with trigonometry.
(I might write a program to show it.)

However for an experiment we could do it with a two arm table if one of the arms was a LT. Then we would time align at the start… or we would just do a cross correlation every so often to show the offset as a function of time, which is the time delay as a function of platter position.

This method (being a relative measurement) would remove all the W&F and platter speed, but still probably includes some effect from the offset holes.