Papst motor running 140% fast - Elac 10H 50Hz turntable

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empireboy
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Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 28 Jun 2015 15:29

I live in the USA and picked up what appears to be an unused Elac 10H turntable produced circa 1965. It features the legendary Papst hysteresis motor.

I'm experiencing a speed issue in which the turntable is running about 2.4x fast per a given speed. For example, at the 33 RPM setting, my strobe disc shows the platter is rotating at a consistent 80 RPM.

I checked the idler wheel and it perfectly aligns with each of the speed steps on the pulley (16,33,45 and 78), so I was able to rule out a misaligned idler wheel as the cause of the speed issue.

The printed serial number sticker says "110 volts, 0,14 amps, 60 cycles AC." However, at "50Hz" is stamped on top of the sticker in blue whereas the rest of the text is printed. Perhaps this is why the unit is unused as the US is 60Hz. This may indicate that the motor has a 50Hz pulley instead of 60Hz. However, a 50Hz pulley used in the US (60Hz) should only result in a speed deviation of a few percent.

I'm unclear on what is causing this unit to run 140% fast. When comparing capacitors on this unit to known 60Hz 10h models on eBay, I see that my 50Hz unit has what appears to be extra 1uF silver capacitor piggybacked on top of another paper capacitor. Unclear if this is a causal factor or if any of the three capacitors used are leaking or dried up and if that could explain the massive speed overrun.

Any help on how to achieve correct pitch beyond a potential 60Hz pulley would be greatly appreciated.

Here are some pictures and I found a couple of schematics of the 110V and 220V versions. Unclear if my 50Hz unit is 110V vs 220V as the sticker says 110V but has a 50Hz stamp on top of it.

Thoughts?

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by Alec124c41 » 28 Jun 2015 16:25

Most of these motors are the same, both sides of the pond. Belt drive motors run at 250 RPM on 50 cycles, 300 RPM on 60 cycles. The difference in voltage is corrected in the wiring, and should not affect speed.
Different sized pulleys or spindles on the motor accommodated the different speeds.
The wrong pulley/spindle would result in a 20 percent error.
That all said, I had the same problem with an old Ariston, which apparently had the correct pulley, etc, and still ran way too fast. One of these days, I will get back to it, and find a better solution than adding a quarter inch of tape to the sub-platter.
I'm watching to see if an answer comes up here.

Cheers,
Alec

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 28 Jun 2015 18:36

Here's a comparison pic of a 60Hz Elac 10H for the US market I found online to my 10H unit rated at 50Hz. Notice that the 60Hz version lacks the piggybacked silver can cap on the 50Hz unit (my unit). The third image is an Ero cap that appears to be common to all versions. This Ero cap is tethered to the ignition switch. Thoughts?

Below: 60Hz US Elac 10H (not my unit):
http://www.audiokarma.org/forums/attach ... 1435512641


Below: 50Hz Elac 10H (my unit). Note "piggybacked" silver can cap.
http://www.audiokarma.org/forums/attach ... 1435512641

Below: 50Hz Elac 10H (my unit). This Ero cap appears to be tethered to the ignition switch and appears to also be present in the 60Hz units.
http://www.audiokarma.org/forums/attach ... 1435512641

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 28 Jun 2015 20:03

In case the images weren't displaying properly earlier, I've uploaded them to an image hosting site and am posting them below:

http://s2.postimg.org/qw3sfpycp/IMG_0201.jpg

http://s11.postimg.org/d05fzxp77/IMG_0202.jpg

http://s27.postimg.org/q6oczptv7/IMG_0214.jpg

http://s30.postimg.org/umopa72jl/IMG_0170.jpg

http://s18.postimg.org/ls02kp621/IMG_0325.jpg

http://s23.postimg.org/4ryzuok2j/IMG_0339.jpg

Below 115V/60Hz from service manual.

http://s21.postimg.org/k3vcw765j/115v60hz.jpg

Below 220V/50Hz from service manual.

http://s22.postimg.org/504jqls4x/220v50hz.jpg

Image below a 60HZ 10H (NOT MY UNIT). Note absence of silver piggybacked capacitor.

http://s1.postimg.org/iacu99bn3/elac10_H_60hz.jpg

My unit below (50Hz). Note presence of silver "piggybacked" capacitor.

http://s30.postimg.org/mc7hg3wdd/elac10_H_50hz.jpg

And the Ero cap on my unit tethered to the ignition switch that appears to be common to both the 50Hz and 60Hz units.

http://s22.postimg.org/jfmgpi569/ero_ca ... switch.jpg

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by ludite » 28 Jun 2015 20:10

hi, voltage x hz. divided by the number of poles - slip = rpm. is the basic motor speed calculation, so one of those factors is off. it's not slip i dont know about your specific motor but many motors can be wired for multiple speeds internally by adding or removing poles. the hz sticker is likely referring to the pulley
hope this helps

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 28 Jun 2015 20:52

Found this in the German Elac 10H service manual and ran it through Google Translate. Not sure how accurate the translation is. Your thoughts?

http://s14.postimg.org/e92juwrbl/german ... manaul.png

Mains connection

To connect the power cord is on the bottom of the chassis plate, a two-pole terminal strip (s. Fig. 3) attached to a two-wire power cord must be connected with plugs. One check before inserting the power plug whether the existing mains voltage and frequency correspond to the data on the nameplate of the appliance.

Devices MIRACORD 10 are only for mains frequency 60 Hz supplied. However, a switch from 110 volt mains voltage to 220 V by connecting the two winding halves of the engine - instead of the parallel connection at 110 V mains voltage - possible (see enclosed circuit diagram). When executing MIRACORD 10H is a change from 110 to 220 V and vice versa and such from 60 to 50 Hz and vice versa always only be achieved by replacing the entire engine and the phase capacitor.

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by Coffee Phil » 29 Jun 2015 08:15

Hi Empireboy,

Please check that speed again. This time put a piece of tape on the edge of the platter and time it for one minute. I am almost sure you will find it is turning at 40 RPM. 40 RPM will be stationary with an 80 RPM Strobe disc. It turns out that 40 RPM is also 6/5ths of 33 1/3 RPM which is precisely the speed it should turn if it is set up for 50 Hz and you are running it on 60 Hz.

I am sure you will either need to find a 60 Hz pulley for it or come up with a 50 Hz power source. The 50 Hz may actually be easier to come up with than that pulley.

Do the test and if I am right we can talk about the 50 Hz source. It really is not all that bad.

By the way 40 RPM is 20% fast for 33 1/3 RPM. I'd call that more that a few percent.

I am guessing that you have the US machine and someone wanted to use it either in Europe or the 50 Hz parts of Japan. If it was used in Europe they probably used a step down transformer as with the hysteresis motor the voltage can not be changed. I believe it is a three phase delta connected stator.

Phil

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 29 Jun 2015 12:45

Coffee Phil wrote:Hi Empireboy,

Please check that speed again. This time put a piece of tape on the edge of the platter and time it for one minute. I am almost sure you will find it is turning at 40 RPM. 40 RPM will be stationary with an 80 RPM Strobe disc. It turns out that 40 RPM is also 6/5ths of 33 1/3 RPM which is precisely the speed it should turn if it is set up for 50 Hz and you are running it on 60 Hz.

I am sure you will either need to find a 60 Hz pulley for it or come up with a 50 Hz power source. The 50 Hz may actually be easier to come up with than that pulley.

Do the test and if I am right we can talk about the 50 Hz source. It really is not all that bad.

By the way 40 RPM is 20% fast for 33 1/3 RPM. I'd call that more that a few percent.

I am guessing that you have the US machine and someone wanted to use it either in Europe or the 50 Hz parts of Japan. If it was used in Europe they probably used a step down transformer as with the hysteresis motor the voltage can not be changed. I believe it is a three phase delta connected stator.

Phil
Hi Phil,

Using a KAB Speed Strobe, the platter spins at a precise and consistent 80 RPM when the 33.3 RPM speed is selected.

Someone suggested to me:

"It is a split-field motor, and both fields need to be connected. If only half are connected, there are only half as many poles turning the rotor, so it would turn twice as fast. One field is not connected or open."

I think this theory of only half the fields being connected may be correct. Currently, at the 33.3 RPM setting, the platter is rotating at a rock solid 80 RPM per a KAB Strobe. So twice as fast (2 x 33.3) = 66.6 RPM. Then if we account for the 50Hz pulley instead of a 60Hz pulley the ratio is 1.2 (60/50=1.2). 66.6 RPM x 1.2 = 79.92 or rounding up: 80 RPM -- the precise speed the platter is rotating at when the selector switch is at 33.3 RPM.

Therefore, this leads me to conclude that even though the unit doesn't say 220V (the sticker says 110V 50Hz), it's actually set up for 220V 50Hz operation.

Now the question is: do I need to find a donor 60Hz motor? Or can I remove the silver can cap and swap pulleys keeping the existing motor?

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by KentT » 29 Jun 2015 13:24

Got to change the motor. Papst motors must be changed. They're designed for one voltage/one frequency use only. If this were a 10 non H, pulley change and voltage change and you'd be good to go.

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by Coffee Phil » 29 Jun 2015 16:00

Hi Empireboy,

The KAB strobe has no 40 RPM markings as that is not a common turntable speed. 80 RPM is a common speed (Edison, Pathe, and some others). With strobes you can get a stationary pattern at sub-multiple speeds. The 33 1/3 strobe markings on my turntable are stationary at 16 2/3 RPM. That is just the way it is with strobes.
There is no conceivable way that four pole synchronous motor will turn fast enough on 60 Hz to make that platter spin at 80 RPM when set at 33 1/3 RPM. Count the revolutions in one minute. Even if you can't get a precise number it will be close enough to figure which sub-multiple of 80 RPM you are dealing with. The fact that 40 RPM is 6/5 of 33 1/3 RPM strongly points to it turning at 40 RPM.

Phil
empireboy wrote:
Coffee Phil wrote:Hi Empireboy,

Please check that speed again. This time put a piece of tape on the edge of the platter and time it for one minute. I am almost sure you will find it is turning at 40 RPM. 40 RPM will be stationary with an 80 RPM Strobe disc. It turns out that 40 RPM is also 6/5ths of 33 1/3 RPM which is precisely the speed it should turn if it is set up for 50 Hz and you are running it on 60 Hz.

I am sure you will either need to find a 60 Hz pulley for it or come up with a 50 Hz power source. The 50 Hz may actually be easier to come up with than that pulley.

Do the test and if I am right we can talk about the 50 Hz source. It really is not all that bad.

By the way 40 RPM is 20% fast for 33 1/3 RPM. I'd call that more that a few percent.

I am guessing that you have the US machine and someone wanted to use it either in Europe or the 50 Hz parts of Japan. If it was used in Europe they probably used a step down transformer as with the hysteresis motor the voltage can not be changed. I believe it is a three phase delta connected stator.

Phil
Hi Phil,

Using a KAB Speed Strobe, the platter spins at a precise and consistent 80 RPM when the 33.3 RPM speed is selected.

Someone suggested to me:

"It is a split-field motor, and both fields need to be connected. If only half are connected, there are only half as many poles turning the rotor, so it would turn twice as fast. One field is not connected or open."

I think this theory of only half the fields being connected may be correct. Currently, at the 33.3 RPM setting, the platter is rotating at a rock solid 80 RPM per a KAB Strobe. So twice as fast (2 x 33.3) = 66.6 RPM. Then if we account for the 50Hz pulley instead of a 60Hz pulley the ratio is 1.2 (60/50=1.2). 66.6 RPM x 1.2 = 79.92 or rounding up: 80 RPM -- the precise speed the platter is rotating at when the selector switch is at 33.3 RPM.

Therefore, this leads me to conclude that even though the unit doesn't say 220V (the sticker says 110V 50Hz), it's actually set up for 220V 50Hz operation.

Now the question is: do I need to find a donor 60Hz motor? Or can I remove the silver can cap and swap pulleys keeping the existing motor?

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 01 Jul 2015 00:32

Hi Coffee Phil

You were right! I put a quarter on the platter and counted revolutions and it was about 41 RPM in a minute when the selector switch was at 33.3 RPM.

So is this turntable 110V (not 220V) after all? And is the only thing I need to change is the pulley from 50Hz to 60Hz? By the way, as I don't have a plinth and cartridge for this yet, I haven't played any records, so I only went on the KAB Strobe which showed a lock on 80RPM. Your observation about 40RPM being a sub multiple makes sense.

Also, this unit appears different from other 110V units by having BOTH a silver 1uf capacitor sitting on top of what appears to be a 3uf paper capacitor (it's in a sheath and I can't confirm the exact value). The 3uf paper capacitor is observed in pictures of other 110V 60Hz units. Do I need to remove the silver 1uf capacitor?
Coffee Phil wrote:Hi Empireboy,

The KAB strobe has no 40 RPM markings as that is not a common turntable speed. 80 RPM is a common speed (Edison, Pathe, and some others). With strobes you can get a stationary pattern at sub-multiple speeds. The 33 1/3 strobe markings on my turntable are stationary at 16 2/3 RPM. That is just the way it is with strobes.
There is no conceivable way that four pole synchronous motor will turn fast enough on 60 Hz to make that platter spin at 80 RPM when set at 33 1/3 RPM. Count the revolutions in one minute. Even if you can't get a precise number it will be close enough to figure which sub-multiple of 80 RPM you are dealing with. The fact that 40 RPM is 6/5 of 33 1/3 RPM strongly points to it turning at 40 RPM.

Phil

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by Coffee Phil » 01 Jul 2015 01:02

Hi Empireboy,

There may be markings on the motor to confirm the voltage, however if your motor has sufficient torque while running on 120 Volts it is a 120 Volt motor.

If you can secure a 60 Hz pulley that would be the easiest solution. If the pulley is not to be had you might look for a machine shop who will make one for you. I highly recommend that you just let them use your pulley as a model and not machine it. Have them copy it with the same ID hole and length but scale the OD of each step precisely 5/6 ths of the diameter of each of the steps on the 50 Hz pulley.

If this turns out to be too expensive, then we can talk about a 50 Hz power source. The reason I urge you to not let them molest to old pulley is that the 50 Hz solution can be a back up should the machining not go well. Really the 50 Hz thing is not all that bad. With an old amplifier, a function generator from eBay, and an HVAC control transformer you should be able to do this for about $100.

If you find a machinist who is willing to take this on we should look at the phase shift cap. The value is a function of frequency. Is it the 60 Hz value or was it changed with the pulley? Who knows? If it is off the motor will hum slightly. Lacking documentation the value can be tuned for least vibration from the motor.

Phil
empireboy wrote:Hi Coffee Phil

You were right! I put a quarter on the platter and counted revolutions and it was about 40 RPM in a minute when the 33.3 RPM was selected.

So is this turntable 110V (not 220V) after all? And the only thing I need to change is the pulley from 50Hz to 60Hz? By the way, as I don't have a plinth and cartridge for this yet, I haven't played any records, so I only went on the KAB Strobe which showed a lock on 80RPM. Your observation about 40RPM being a sub multiple makes sense.
Coffee Phil wrote:Hi Empireboy,

The KAB strobe has no 40 RPM markings as that is not a common turntable speed. 80 RPM is a common speed (Edison, Pathe, and some others). With strobes you can get a stationary pattern at sub-multiple speeds. The 33 1/3 strobe markings on my turntable are stationary at 16 2/3 RPM. That is just the way it is with strobes.
There is no conceivable way that four pole synchronous motor will turn fast enough on 60 Hz to make that platter spin at 80 RPM when set at 33 1/3 RPM. Count the revolutions in one minute. Even if you can't get a precise number it will be close enough to figure which sub-multiple of 80 RPM you are dealing with. The fact that 40 RPM is 6/5 of 33 1/3 RPM strongly points to it turning at 40 RPM.

Phil

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 01 Jul 2015 01:16

The markings on the motor (see below) appear to say 115V (directly below the text "HSZ"), but it also appears Elac intentionally scratched off the Hz and MF values. I believe these values would have originally been listed on the motor as 60Hz and 3MF, respectively. So it appears that Elac modified the unit to run at 50Hz? And they added a 1MF can cap on top of an apparently already existing 3MF paper cap. If that's the case, would the pulley and 1MF can cap be the only modifications that need to be reversed to run the unit in the USA? By the way, it appears 110V and 50Hz is the voltage and frequency for Jamaica and Northern Japan. Maybe Elac tweaked the unit for shipment there?

First image below is my motor from the Elac 10H. Second image below is of a Papst motor from an Elac 50H -- 115V 60hz 3MF -- that I found on the web for comparison. Same motor model numbers. Note the scratch offs on my motor where 60 Hz and 3MF should be.

http://s27.postimg.org/q6oczptv7/IMG_0214.jpg

http://s10.postimg.org/kwdf2do13/57_6.jpg

Coffee Phil wrote:Hi Empireboy,

There may be markings on the motor to confirm the voltage, however if your motor has sufficient torque while running on 120 Volts it is a 120 Volt motor.

If you can secure a 60 Hz pulley that would be the easiest solution. If the pulley is not to be had you might look for a machine shop who will make one for you. I highly recommend that you just let them use your pulley as a model and not machine it. Have them copy it with the same ID hole and length but scale the OD of each step precisely 5/6 ths of the diameter of each of the steps on the 50 Hz pulley.

If this turns out to be too expensive, then we can talk about a 50 Hz power source. The reason I urge you to not let them molest to old pulley is that the 50 Hz solution can be a back up should the machining not go well. Really the 50 Hz thing is not all that bad. With an old amplifier, a function generator from eBay, and an HVAC control transformer you should be able to do this for about $100.

If you find a machinist who is willing to take this on we should look at the phase shift cap. The value is a function of frequency. Is it the 60 Hz value or was it changed with the pulley? Who knows? If it is off the motor will hum slightly. Lacking documentation the value can be tuned for least vibration from the motor.

Phil

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by Coffee Phil » 01 Jul 2015 01:34

Hi Empireboy,

What you suspect is likely true. 50 Hz would require a larger cap. Put a mechanic's stethoscope (Harbor Freight has them) on the motor and listen with the 1 micro-farad cap connected and disconnected. My expectation is that it will be quieter with the cap removed (on 60 HZ). Retain the cap as you will want it back in if the 50 Hz solution is what you will have to do.

I believe you are correct that the frequency and cap value was probably marked on the motor at one time. The Papst hysteresis motor in my R-O-K Rondine 2 has those markings.

Below is my "Redneck Speedbox" experiment with my Rondine 2:

26542d

The function generator is an HP 3311, the amp is a Fisher 80 AZ, and the the transformer is a 24 Volt wall-wart. For sure you don't need a nice tube amp like that to make electrical power to turn a turntable but it was handy. Some grunt ~30 Watt sand thing will do fine. I was generating greater than 60 Hz as this was an experiment to get other speeds from the Rondine which is 33 1/3 only. I was able to achieve 45 RPM. 78.26 RPM is yet to come. The same concept can be used to make 50 Hz.

Phil

[quote="empireboy"]The markings on the motor (see below) appear to say 115V, but it also appears Elac intentionally scratched off the Hz and MF values. I believe these values would have originally been listed on the motor as 60Hz and 3MF, respectively. So it appears that Elac modified the unit to run at 110V 50Hz? And they added a 1MF can cap on top of a 3MF paper cap. If that's the case, would the pulley and 1MF can cap be the only modifications that need to be reversed to run the unit in the USA? By the way, it appears 110V and 50Hz is the voltage and frequency for Jamaica and Northern Japan. Maybe Elac tweaked the unit for shipment there?

First image below is my motor. Second image below is an image of a known 60hz 115V motor from the web for comparison. Same model numbers. Note the scratch offs on my unit where Hz should be.

http://s27.postimg.org/q6oczptv7/IMG_0214.jpg

http://s8.postimg.org/qfij5g0ms/115elac.jpg
Last edited by Coffee Phil on 01 Jul 2015 01:57, edited 1 time in total.

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Re: Papst motor running 140% fast - Elac 10H 50Hz turntable

Post by empireboy » 01 Jul 2015 01:44

Has anyone tried to remove a pulley from a Papst hysteresis motor? If so, what is the process to remove it?

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