[simoon]

In another thread I mentioned that I was able to purchase an Ariston RD11 for pretty cheap. I just received it, and it is in great shape. The bearing is dead quite, the springs are in good shape, and it's cosmetically good too.

But here's the rub. It's configured for 50hz. The modification is very simple to change to 60hz, bypassing a resistor with wire, and replacing a .22 micro farad cap with a .18 mic cap. They refer to this as the 'motor start cap'.

Can anyone point me to a source for a suitable cap? I drove to 3 electronic stores in the L.A. area today under the impression I'd be able to find the cap easily.

The .22 that is installed is a square form factor, no voltage is given and the brand is Rifa. I'm not even sure what type of cap it is, other than non-polarized.

Thanks in advance to all the TT pros here!

[neobop]

http://www.mouser.com/Passive-Components/Capacitors/Film-Capacitors/Polyester-Film-Capacitors/_/N-5g7w?P=1z0wps8

Check the data sheet to make sure they're nonpolarized. If you're not sure you can call. Tolerance and voltage should be listed on each item.

neo

[Wayner]

Most of the starting caps I have are rated at 600 volts. Hurst electric motor company may be able to help you with a cap.

Wayner

[BaMorin]

In another thread I mentioned that I was able to purchase an Ariston RD11 for pretty cheap. I just received it, and it is in great shape. The bearing is dead quite, the springs are in good shape, and it's cosmetically good too.

But here's the rub. It's configured for 50hz. The modification is very simple to change to 60hz, bypassing a resistor with wire, and replacing a .22 micro farad cap with a .18 mic cap. They refer to this as the 'motor start cap'.

Can anyone point me to a source for a suitable cap? I drove to 3 electronic stores in the L.A. area today under the impression I'd be able to find the cap easily.

The .22 that is installed is a square form factor, no voltage is given and the brand is Rifa. I'm not even sure what type of cap it is, other than non-polarized.

Thanks in advance to all the TT pros here!

Do you have the correct drive pulley?

[simoon]

Thanks everyone.

Neobop, that Mauser link was just what I was looking for.

They have a suitable cap that is rated at 600 volts as per Wayner's recommendation.

BaMorin...crap! Why didn't I think about the 60hz pulley?! I guess I was so excited about the price I got the table for, I didn't think through all the variables.

Anyone have any help on getting the pulley? I searched pretty hard for one already this morning, to no avail.

I guess I could have one machined, but how would I know what the diameter should be for the increased motor RPM?

[rcag_ils]

What a bummer without the correct pulley, you may want to contact Linn for one, Ariston RD-11 and Linn are pretty close. They may charge you $100 for it though

[BaMorin]

Thanks everyone.

Neobop, that Mauser link was just what I was looking for.

They have a suitable cap that is rated at 600 volts as per Wayner's recommendation.

BaMorin...crap! Why didn't I think about the 60hz pulley?! I guess I was so excited about the price I got the table for, I didn't think through all the variables.

Anyone have any help on getting the pulley? I searched pretty hard for one already this morning, to no avail.

I guess I could have one machined, but how would I know what the diameter should be for the increased motor RPM?

Square section belt, or round section? Getting one machined might be cheaper than buying one.

[simoon]

Square section belt, or round section? Getting one machined might be cheaper than buying one.

It's a flat belt.

I was thinking that I may have to get one machined.

[rcag_ils]

I don't see how could machining one would be cheaper than buying one.

After you have one machined, please let me know how much it cost and where the machine shop is, so I could get a bunch of parts machined.

[BaMorin]

It's a flat belt.

I was thinking that I may have to get one machined.

hmmm......must be original type used by Linn as well. My RD11S had a square cut belt that rotated 90deg. from pulley to subplatter. The pulley was 90deg "V" cut. 

The folks on the Ariston forum at Vinylengine may be able to give you exact answers on where to purchace.

[simoon]

What a bummer without the correct pulley, you may want to contact Linn for one, Ariston RD-11 and Linn are pretty close. They may charge you $100 for it though

I just talked to a Linn dealer in my area (Brooks Berdan) and even they aren't sure the pulleys are compatible.

But on the plus side, the pulley is only $30. And they have one in stock.

I might actually get one of these - http://cgi.ebay.com/MOSE-Hercules-acclaimed-External-PSU-Linn-LP12-/320631417330?pt=LH_DefaultDomain_0&hash=item4aa71f29f2

[BaMorin]

I just talked to a Linn dealer in my area (Brooks Berdan) and even they aren't sure the pulleys are compatible.

But on the plus side, the pulley is only $30. And they have one in stock.

I might actually get one of these - http://cgi.ebay.com/MOSE-Hercules-acclaimed-External-PSU-Linn-LP12-/320631417330?pt=LH_DefaultDomain_0&hash=item4aa71f29f2

Measure your subplatter, get a measurement of the diameter of the pulley, check to see if the motor spindle is the same diameter.........ask for a measurement of the Linn subplatter. If both are the same diameter, and the motor spindles are the same, it would have to work. You may need to run a Linn belt if the face of the pulley is different.

[rcag_ils]

I just talked to a Linn dealer in my area (Brooks Berdan) and even they aren't sure the pulleys are compatible.

Of course they will tell you that to free them from all liability. If it's a Ariston RD-11, Linn pulley will be compatible, they are the same tables, it's worth a try. I have an Ariston, check it out.

[Wayner]

Just to recap the problem a bit, we have a 50 hz synchronous motor that is now being run on 60 cycles. So the motor runs too fast, correct?

So if we have a motor that was designed to run at 50 hz with a pulley that was also designed to run at 50 hz, and now you are running this combo at 60 hz, a 50 hz pulley is what you already have. You need an even smaller pulley (custom) to make it run at the proper speed.

A 50hz motor run at 60 hz is witnessing a .1666667 increase in speed. The 50 hz pulley will have to have it's circumference reduced by the same amount, that will give you the correct diameter.

It's all about the math.

Wayner

[simoon]

A 50hz motor run at 60 hz is witnessing a .1666667 increase in speed. The 50 hz pulley will have to have it's circumference reduced by the same amount, that will give you the correct diameter.

It's all about the math.

Wayner

Doh....

Well don't I feel like a moron?

Thanks for pointing out simple ratios to me. I guess my mind is too filled with binary and hex.

[BaMorin]

Doh....

Well don't I feel like a moron?

Thanks for pointing out simple ratios to me. I guess my mind is too filled with binary and hex.

Computers will do that 

[simoon]

Thanks for all the help all!

I solved my issue in a completely different way, and I got a better sounding table out of my solution.

I went with one of these (a Hercules PS clone) -

http://cgi.ebay.com/Power-board-LINN-LP12-Regar-Thorens-33-and-45-RPM-New-/150577940124?pt=LH_DefaultDomain_0&hash=item230f25069c

I mounted in an outboard chassis (I didn't exactly feel safe installing a Chinese board of unknown build quality in a wooden TT, even with a fire extinguisher close by).

The results are brilliant! I can't directly compare the it to an RD11 without one, but I do know what the improvements are on a Linn with a Hercules power supply.

110V in, 110V out @ 50hz (67.5 hz for 45) to the motor controlled by crystal oscillators. No need to mess with modifying the onboard PS, no need to worry about getting a 60hz pulley. And I can guarantee it sounds better. At a $100, it probably didn't cost any more than getting a new pulley or the existing one machined.