I doubt this is exactly true there is no side to side constraint except by magnetic force, at that distance from the base I remain sceptical that this could be done well enough. An out of round LP will push where a normal TT has a totally stiff bearing in that direction. The wobble is obvious in all the demos and a warped LP would seem virtually un-playable.
There was a big initiative years ago, and we built a nice demo. There were not enough living rooms big enough to get any traction. This has changed again and now folks are talking about it.
This idea is perfect if you like a complete instable bearing.
What I don't understand is that simply having a stiff center shaft and levitating and rotating the table magnetically would have been equally cool and might actually work.
😕 The only link is to a globe toy, which BTW was around in 1970 in a tiny form, 2" metal globe levitated that you could spin.
I thought Stanton sold that turntable 30 years ago.
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Scott,
Adding a center shaft would take away the illusion of "Look Ma, No Hands" and that would wreck the marketing of this stupid TT design for the KickStarter crowd that helps to finance these projects. A simple center shaft as you say would solve real problems and if I had to do that and keep the look I would use a clear plastic or glass rod for the center to keep the look of levitation without ruining the concept but making it work as you understand of at least one, really two degrees of freedom you would take away with a center shaft.
Adding a center shaft would take away the illusion of "Look Ma, No Hands" and that would wreck the marketing of this stupid TT design for the KickStarter crowd that helps to finance these projects. A simple center shaft as you say would solve real problems and if I had to do that and keep the look I would use a clear plastic or glass rod for the center to keep the look of levitation without ruining the concept but making it work as you understand of at least one, really two degrees of freedom you would take away with a center shaft.
May I go slightly OT? Need some help.
Guido Tent gave me a nice Brookdeal Nanovolt Preamplifier Type 431. Brookdeal is/was a UK company and this thing is a 400pV/RtHz 60dB measurement preamp. I just attached 4 new 9V batteries and it seems to work well, except that the gain is more like 70dB (not that I complain at this point).
100uV 1kHz input gives a nice 360mV at the output. Some mains hum, as is to be expected at those levels.
I've spend hours cruising the 'net to find any documentation or a manual for it, to no avail. All I found was a list of equipment where it was on, at a university, giving the basic 400pV/RtHz spec.
Last resort is the assembled knowledge and experience here. Anybody know more of this?
Jan
Guido Tent gave me a nice Brookdeal Nanovolt Preamplifier Type 431. Brookdeal is/was a UK company and this thing is a 400pV/RtHz 60dB measurement preamp. I just attached 4 new 9V batteries and it seems to work well, except that the gain is more like 70dB (not that I complain at this point).
100uV 1kHz input gives a nice 360mV at the output. Some mains hum, as is to be expected at those levels.
I've spend hours cruising the 'net to find any documentation or a manual for it, to no avail. All I found was a list of equipment where it was on, at a university, giving the basic 400pV/RtHz spec.
Last resort is the assembled knowledge and experience here. Anybody know more of this?
Jan
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This guy can probably help you. Worked at Brookdeal, his free book looks very nice and old school BTW.
https://sites.google.com/site/lockinamplifiers/home
Or the principle of this strange little company in the Channel Is.
EM D.C. PICOVOLTMETER MODEL P13 Specification.
This gets the no cigar award but will show you their basic design philosophy.
https://doc.xdevs.com/doc/_Legacy/Brookdeal/5003 NANOVOLT PREAMP.pdf
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Yes. I met an engineer that claimed he was the one that designed that. He showed up to as a guest speaker at my toast masters group in the mid eighties. Brought a levitated globe with him. He seemed a bit too young though to have done this in the early 70s.
But who knows. He might been a non smoker and just looked young.
A few years later a giant version of the globe showed up at Vancouver BC's Science World.
I worked there 6 weeks before the grand opening. Some of the guys at Science World opened the control box up just to find a couple of TL081 op amp controlling the whole thing.
They paid $50000.00 for the thing.
No, my senior faculty advisor did one as a consultant it might never have made it to market at the time.
He might have meant that he was the EE that designed the globe for Pacific Levitation and I interpreted it as meaning the inventor.
This idea is perfect if you like a complete instable bearing.
Exactly. Not like we're bereft available maglev bearing designs (most of the turbomolecular pumps used in fab equipment are maglev, and I'm sure that's far from the only usage), but they certainly lack the "Look ma, no hands!" effect.
OK, lots of talk about rotating the platter, how about interference?
we have the creation of a magnetic field used to hold and turn the platter in space, then we have the typical phono cartridge on the upper surface of the disc. A device that works by magnetic principles. So, how much leakage are we looking at here, what frequencies might we expect the platter to be operating at, etc. Do we need to go to piezo cartridges to use this neato toy?
curious
Alan Garren
we have the creation of a magnetic field used to hold and turn the platter in space, then we have the typical phono cartridge on the upper surface of the disc. A device that works by magnetic principles. So, how much leakage are we looking at here, what frequencies might we expect the platter to be operating at, etc. Do we need to go to piezo cartridges to use this neato toy?
curious
Alan Garren
Next is a nuclear driven and stabilized record player, work is in progress...
Project Orion Nuclear Propulsion - 1950s Tests | Unclassified Video
Project Orion Nuclear Propulsion - 1950s Tests | Unclassified Video
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