making sense of motor specifications

[lensmanMk2]

well ive been ploughing through motor specs the past few days trying to find a replacement for my turntable and found one that might fit the bill, but im not 100% sure:

http://www.premotec.com/pdf/brushles...84-wire%29.pdf

the only trouble is trying to make sense of the output on a working lt5V turntable motor

Vr pin: varies from 2.75v > 2.79v when speed is switched, then settles back to 2.75v irrespective of speed selected

C pin: varies from 1.40v > 1.43v when switched, then settles back to 1.40v irrespective of speed selected

feed voltage pin: 11.20v normal then swings upto 11.30 when switched, settles back to 11.20v irrespective of speed selected

this is crazy.. shouldnt at least one of these stay at a higher/lower value when the speed is switched? for example if one is the tacho feedback, and another the rpm adjuster? the schematics give tons of scope info for the tonearm, but nothing for checking the actual main drive motor

so does anyone out there have any idea how this motor can actually function.. and if so is it even possible to fit a new one into this existing circuit?

thanks