Tonearm not balanced correctly (horizontally)

[Ralius]

So I purchased a Philips 23FP421 (vintage, and not a lot to look up about it) not long ago, and it has worked perfectly fine up until just recently.
When playing records, they tend to skip increasingly frequently towards the end of the side. I figured out that there is a point at which the tonearm just isn't balanced correctly and will swing back outwards, even with the anti-skating all the way down (so it shouldn't swing out). What can be done about this? I'm pretty sure the tonearm is balanced correctly vertically, but there's just the one point where it seems unbalanced.
Also the sound can be quite wobbly, even though it is matched perfectly with the fine pitch adjust on it.

Any ideas on either of these issues? I can post pictures if needed.

 

[John James]

I do believe the anti-skate is to keep the arm from skating in, towards the center. I think you are adjusting the wrong way. (I could be wrong!)

 

[Ralius]

Well it plays perfectly fine for the majority of a side, but skips more at the end. I have tried increasing the skating, and that does just pull it outwards for some reason.

 

[MRL_Audio]

What cartridge? How old is the stylus? What VTF are you tracking at?

 

[heyraz]

I'm pretty sure the tonearm is balanced correctly vertically, but there's just the one point where it seems unbalanced.

Is the table itself level?

I do believe the anti-skate is to keep the arm from skating in, towards the center. I think you are adjusting the wrong way. (I could be wrong!)

Centrifugal force is the action here and it would cause the tonearm to move away from the spindle. For example, if you put a ball bearing on the turntable while it was spinning, it would "skate" away from the spindle. Anti-skate is applied to pull it back towards the spindle.
When the tonearm is balanced for zero tracking force, it should float stationary. If it moves one way or another it's lateral balance is off, but not all arms have an adjustment for lateral balance. My next guess is that the turntable itself is not level.

Also the sound can be quite wobbly, even though it is matched perfectly with the fine pitch adjust on it

.
I'm assuming you are checking the speed with a strobe. A record with it's hole not perfectly centered will induce a wow and flutter effect which should be visible to the naked eye. Does the cartridge move back and forth as the record spins?

 

[Montycat]

Centrifugal force is the action here and it would cause the tonearm to move away from the spindle. For example, if you put a ball bearing on the turntable while it was spinning, it would "skate" away from the spindle. Anti-skate is applied to pull it back towards the spindle

Absolutely wrong. Anti-skake pulls outward.

There might be issues with cartridge alignment, tonearm bearing adjustment, wires binding as the arm moves, or other factors at play here.

Anti-skate springs or weights are often not terribly precise and might not even be working properly at all despite what an indicator might say.

 

[I LIKE MUSIC]

Centrifugal force is the action here and it would cause the tonearm to move away from the spindle. For example, if you put a ball bearing on the turntable while it was spinning, it would "skate" away from the spindle. Anti-skate is applied to pull it back towards the spindle.

To be clear it is not centrifugal force. The inward, not outward skating force results from the offset angle of the phono cartridge with relation to the pivot point of the tone arm and the friction between the stylus and the record. Basic physics.

Your example is not correct.

I have tried increasing the (anti) skating, and that does just pull it outwards for some reason.

That is the way anti-skating function is supposed to function. Its purpose is to counteract inward force caused by the force caused by the friction of the stylus and the record and geometry of the tone arm.

 

[hi*ball]

Sounds like tone arm bearings.

 

[John James]

Try adjusting in the other direction and tell us what happens.

 

[heyraz]

Absolutely wrong. Anti-skake pulls outward.

To be clear it is not centrifugal force.

I stand corrected. Anti-Skate pulls the tonearm out I always confuse centrifugal and centripetal forces. My apologies.

I should have thought more about this before I wrote. My arm uses a weight and pulley but I didn't pay attention to the details because I don't use it. Even though the weight is to the left, the connection is behind the pivot which would pull the arm out, which is something I should have checked before writing.

The OP never stated which way the record skips, forward or backward. I agree with MRL_Audio, the VTF should be verified with an accurate scale. I use the Shure SFG-2 and was surprised how far off the VTF was when I relied on the counterbalance dial.

It also might be time for a new stylus.

 

[rothwellaudio]

I do believe the anti-skate is to keep the arm from skating in, towards the center. I think you are adjusting the wrong way. (I could be wrong!)

No, you're not wrong.

Well it plays perfectly fine for the majority of a side, but skips more at the end. I have tried increasing the skating, and that does just pull it outwards for some reason.

What he said above. Read it again.

 

[Pronto]

My guess is a dirty needle.

 

[Dadbar]

Two things to watch out for that I've experienced

1) On one turntable I was using a record clamp with a Shure V15 II that had the stylus guard up. That stylus guard was rather big and it was physically bouncing off the record clamp when it got to the end of the side. Removing the guard cured the problem.

2) On another automatic turntable (a Dual 1229) the trip pawl mechanism needed lube and it would bind when the arm got to the end of the side. A good lube of the pawl fixed the problem

 

[I LIKE MUSIC]

Anti-Skate pulls the tonearm out I always confuse centrifugal and centripetal forces.

You are getting there, but it is not centripetal force either.

 

[Ralius]

Thanks for all the help guys. The skating doesn't seem to be the issue, considering that if I have it one way (at 0), the tonearm stays where it is. If I adjust it the whole way (to 5), it will constantly move outwards, which is not what I want, so I keep it at 0.

The tonearm only pulls back outwards at this specific point. It happens even when I unplug the turntable from the power source. I can get the tonearm to stay where it as just after that point, which almost leads me to believe there might be something inside the turntable itself messing with it, as it almost feels like a lump or something.

To clarify, it has played perfectly fine, but in the last few days this has been happening. It also works fine at the beginning of a side and I have cleaned the stylus. I will check the movement of the cartridge later on today

 

[I LIKE MUSIC]

The skating forces developed are real, but there is some debate about the need for anti-skating. Some well respected turntables do not include anti-skating.

The theory is that it helps keep the stylus in the middle of the record groove and that it is a good thing.

Good luck with your trouble shooting, I hope it turns out to be something simple.

 

[shelly_d]

I looked for information on this model online and found virtually nothing. Is this an auto return or automatic turntable? If so, I would suspect the mechanical arrangement underneath the plinth that senses the tonearm position and engages and lifts and returns the tonearm to be faulty or in need of adjustment. The problem sounds more mechanical in nature then setup related, at least to me it does.

Shelly_D

 

[Ralius]

Yea there's really nothing online about it at all, but that is the model number on the back of it. It is a belt driven semi-automatic with auto-return.
Is there anything I could try apart from opening it up to have a look? Or would that be a big no-no anyway?

 

[Montycat]

Take the bottom off and have a look. It is likely, as mentioned, either tonearm wires or part of the auto return mechanism binding.

You might need to "put it up on blocks" to be able to watch as it operates as sometimes things that stick right side up won't in other orientations. I have a jig I can use, but perched on 2 stools with a mirror underneath might work for example.

The only thing thing I can think of other than internal bits MIGHT be that the cueing platform is grazing the bottom of the tonearm at just that spot.

I think your table is similar if not the same as the GA-212.

 

[John James]

Thanks for all the help guys. The skating doesn't seem to be the issue, considering that if I have it one way (at 0), the tonearm stays where it is. If I adjust it the whole way (to 5), it will constantly move outwards, which is not what I want, so I keep it at 0.

The tonearm only pulls back outwards at this specific point. It happens even when I unplug the turntable from the power source. I can get the tonearm to stay where it as just after that point, which almost leads me to believe there might be something inside the turntable itself messing with it, as it almost feels like a lump or something.

To clarify, it has played perfectly fine, but in the last few days this has been happening. It also works fine at the beginning of a side and I have cleaned the stylus. I will check the movement of the cartridge later on today

I think that might be an important clue. I just wish I could tell you what it means.