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PostPosted: Feb Mon 07, 2011 6:08 pm 
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Agreed, one of my favorite test records is "Fever" by Peggy Lee. It is really good for a wide range, snapping of fingers, lots of highs, bass etc. Unfortunately, I don't have the ears of a musician who are often much better at picking up issues like wow & flutter, and vibrato, approaching audiophile territory.

I think its a good idea to stay with a particular group of test records, not only for sound, but for early/late start and end of record, bass that will jump a groove if out of compliance or incorrect tracking weight for example. Lotsa fun!

Jack

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 Post subject:
PostPosted: Feb Tue 08, 2011 7:53 am 
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Location: Toledo, Ohio
PhonoJack wrote:
Todd, no in my reply I meant Repair Tech because he has it correct... (who's on first...)

I've seen the debate on ARF about whether changing the diameter of an idler wheel changes the speed of the turntable. It does!

This is why I believe my technique is not a very "hacky" method. In fact it is a very correct method. Here's why:
Whether you are buying a new idler wheel or rebuilding your own, you want to be sure it is tuned specifically to the motor that you're installing with that idler. We've all heard war stories about some of the idlers that are available now, good and bad. Even if you measure your 'new' idler with calipers and it meets the exact diameter specifications, you can't assume your turntable will operate at 45 rpm.

If you're lucky, your motor (one of the 3 or 4 popular motors used by RCA) will operate exactly at 45 rpm at warmed up speed. Some motors don't run at 45 rpm, some run slower or faster and some run hotter or cooler.

You can absolutely increase or decrease the speed of the turntable by shaving the larger or smaller tire. That is how you achieve an exact 45 rpm. By shaving or turning it on a lathe, I think you're creating more work for yourself, because you still need to speed check for 45 rpm each time you put it on a lathe.
I don't mean to pull your leg, :) but there are already enough variables with these little RCA Victor 45 players, such as motor, temperature, too much grease (ha ha), weight of turntable, weight of stack of records and more.

Have fun,

Jack



:lol: LOL... no you still got it wrong Jack.

I know how to change the speed of a turntable, I just asked what was the method you used to change your phone speeds, not IF it can be done. I sure hope I know my basic physics when dealing with gearing since I rebuild transmissions about 6 times a year and I am ASE Certified for it!

Repair Tech replied to some post from Larry about adjusting 45 players and I agreed and added you can also adjust it on RCA 4 speed players by altering the size of the turret wheel's top to bottom aspect ratio same as the idler on the 45 player.

It got messed up in there some where when I replied to Larry and thought it was you then deleted it. Sorry for the confusion...

:lol:

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 Post subject:
PostPosted: Feb Tue 08, 2011 5:50 pm 
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Location: Pro Tech, Philadelphia Pa.
bastardbus wrote:
PhonoJack wrote:
Todd, no in my reply I meant Repair Tech because he has it correct... (who's on first...)

I've seen the debate on ARF about whether changing the diameter of an idler wheel changes the speed of the turntable. It does!

This is why I believe my technique is not a very "hacky" method. In fact it is a very correct method. Here's why:
Whether you are buying a new idler wheel or rebuilding your own, you want to be sure it is tuned specifically to the motor that you're installing with that idler. We've all heard war stories about some of the idlers that are available now, good and bad. Even if you measure your 'new' idler with calipers and it meets the exact diameter specifications, you can't assume your turntable will operate at 45 rpm.

If you're lucky, your motor (one of the 3 or 4 popular motors used by RCA) will operate exactly at 45 rpm at warmed up speed. Some motors don't run at 45 rpm, some run slower or faster and some run hotter or cooler.

You can absolutely increase or decrease the speed of the turntable by shaving the larger or smaller tire. That is how you achieve an exact 45 rpm. By shaving or turning it on a lathe, I think you're creating more work for yourself, because you still need to speed check for 45 rpm each time you put it on a lathe.
I don't mean to pull your leg, :) but there are already enough variables with these little RCA Victor 45 players, such as motor, temperature, too much grease (ha ha), weight of turntable, weight of stack of records and more.

Have fun,

Jack



:lol: LOL... no you still got it wrong Jack.

I know how to change the speed of a turntable, I just asked what was the method you used to change your phone speeds, not IF it can be done. I sure hope I know my basic physics when dealing with gearing since I rebuild transmissions about 6 times a year and I am ASE Certified for it!

Repair Tech replied to some post from Larry about adjusting 45 players and wheel's top to bottom aspect ratio same as the idler on the 45 player. I agreed and added you can also adjust it on RCA 4 speed players by altering the size of the turret

It got messed up in there some where when I replied to Larry and thought it was you then deleted it. Sorry for the confusion...

:lol:


Correct! :wink: :wink:

And to repeat my earlier comment, the "idler only" models cannot and do not depend on the idler size for correct speed.
That is determined solely by the diameter of the (stepped) motor shaft.

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 Post subject:
PostPosted: Feb Tue 08, 2011 9:43 pm 
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Joined: Jan Sat 17, 2009 7:31 am
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Location: USA
RepairTech wrote:
"idler only" models cannot and do not depend on the idler size for correct speed.

"single-tier idler only" models :lol: (we know YOU know that, RT, and probably most on this forum - that's just for the benefit of the any lurkers who probably read our repair threads which they find on google searches for how to repair phonos )

- Bob


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Sat 14, 2018 9:33 pm 
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Does anyone know the RPM of the Alliance RCA 45 motor? I have found source of appliance motors.


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Mon 22, 2019 10:56 pm 
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Joined: Apr Sun 16, 2017 7:57 pm
Posts: 106
After a two pole Alliance motor has been soaked in isopropyl alcohol for 48 hours to clean the bearings, let dry for two days and then re-lubed with turbine oil, is it normal for there still to be a 30 minute warm up period before the motor turns at full speed?

Before the rebuild, the platter turned at a sluggish 43 RPM when cold.

After the motor rebuild, and when COLD, the platter turns at 46.16 RPM. Big improvement. Then 30 minutes later, after the rebuilt motor has WARMED UP, the platter has settled in at 46.73 RPM. So, post rebuild, it increases from 46.16 to 46.73 in the first 30 minutes of warm up.

So there was a massive improvement in initial startup speed after the cleaning and re-lube. Setting aside the fact that it's running fast now (perhaps designed in by the manufacturer making the pulley slightly oversized), the increased platter speed from a cold to warm motor makes me wonder if all the old oil has been removed from the bearing. Is what I'm seeing normal behavior after a rebuild, even when the bearing is completed devoid of old oil and has new turbine oil installed?


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Tue 23, 2019 6:04 pm 
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Joined: Aug Tue 24, 2010 8:56 pm
Posts: 5661
Location: Northeast Florida
zenithconsole wrote:
After a two pole Alliance motor has been soaked in isopropyl alcohol for 48 hours to clean the bearings, let dry for two days and then re-lubed with turbine oil, is it normal for there still to be a 30 minute warm up period before the motor turns at full speed?

Before the rebuild, the platter turned at a sluggish 43 RPM when cold.

After the motor rebuild, and when COLD, the platter turns at 46.16 RPM. Big improvement. Then 30 minutes later, after the rebuilt motor has WARMED UP, the platter has settled in at 46.73 RPM. So, post rebuild, it increases from 46.16 to 46.73 in the first 30 minutes of warm up.

So there was a massive improvement in initial startup speed after the cleaning and re-lube. Setting aside the fact that it's running fast now (perhaps designed in by the manufacturer making the pulley slightly oversized), the increased platter speed from a cold to warm motor makes me wonder if all the old oil has been removed from the bearing. Is what I'm seeing normal behavior after a rebuild, even when the bearing is completed devoid of old oil and has new turbine oil installed?


No, it is not normal. A properly working and properly lubricated motor will run the same hot or cold. If it doesn't, it means that it's either not cleaned sufficiently, or the windings are going bad. For the former; when motor is cold, you should be able to spin it by hand and it should keep spinning for at least a couple of seconds--if it doesn't, it's still gummed up. If it spins freely and it's still taking time to get up to speed, the windings are most likely on their way out.

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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Tue 23, 2019 8:10 pm 
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Thanks. How many days does it take for isopropyl alcohol to completely evaporate from the felt bearings before re-oiling?


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Wed 24, 2019 5:48 am 
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Joined: Aug Tue 24, 2010 8:56 pm
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Location: Northeast Florida
I'm not sure---I never soak anything, I just give the motor a very thorough cleaning with alcohol and cotton swabs. You want to get to a point in cleaning where the cotton swabs no longer turn black from old grease. I see you're using turbine oil, that's the right stuff for the job

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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Wed 24, 2019 3:25 pm 
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zenithconsole wrote:
Thanks. How many days does it take for isopropyl alcohol to completely evaporate from the felt bearings before re-oiling?

If you leave the parts in the sun where they can warm, then
4-6 hours there and the rest of a day is fine to dry out the felts (24hrs).

There are occasions where some folks have had to re-soak
the felt bearing housings to further clean.

Has the idler spindle been cleaned ?

Hotwax


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Wed 24, 2019 6:24 pm 
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Joined: Apr Sun 16, 2017 7:57 pm
Posts: 106
Can rust on the rotor impact speed?

Idler spindle has been cleaned.


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Mon 29, 2019 2:20 am 
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Joined: Apr Wed 09, 2008 3:37 am
Posts: 14346
Location: Little Rock, Arkansas
zenithconsole wrote:
Can rust on the rotor impact speed?

Idler spindle has been cleaned.

Never leave rust on the top or bottom rotor shafts... Clean rust off with #0000 steel wool until it's nice and smooth again...


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 Post subject: Re: Phono Motors Don't Like the Cold Temperatures
PostPosted: Apr Mon 29, 2019 4:30 am 
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Joined: Aug Tue 24, 2010 8:56 pm
Posts: 5661
Location: Northeast Florida
Rust on the sides of the rotor can also affect speed if severe enough. Another thing you can try--spin the rotor by hand and see if it binds up at any point throughout it's rotation. If it comes to a sudden stop, spin the rotor by hand without letting go---if it's binding, you'll feel/hear it

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