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A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 12:00 pm
by doublemike
Help me, please!
Yesterday I've noticed this noise on my Graphophone... What this noise could mean? It seems to have a frequency equal to rpm.
No gears touch some internal cabinet part.
Thank you.
[youtubehq]
http://www.youtube.com/watch?v=T6WiCBx8Fvs[/youtubehq]
Re: A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 12:31 pm
by kirtley2012
Sounds like the governor to me
Re: A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 12:39 pm
by Brad
I am not sure it is the governor as the sound is synchronized with the platter (the governor spins much faster with than the platter).
I would concentrate on the platter and the spindle shaft. It looks like the spindle might be bent or the platter is on crooked and rubbing. Try taking the platter off and determine if the sound disappears and/or the platter is rubbing. If nothing there, they look at lubrication of the spindle and for any wear, damage, or dirt build up on the spiral gear on the spindle.
Re: A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 1:18 pm
by doublemike
Brad wrote:Try taking the platter off and determine if the sound disappears and/or the platter is rubbing.
I did it... the noise is re-appared AND... after two/three seconds of rotation, I've heard an HORRIBLE noise, such as a "ultra-friction" (the same noise that produces a car when someone mistake to use the gears). I've repositioned the platter; the noise is re-appared.
I've noticed that the gear positioned at "nadir" of the spindle (A in the photo) doesn't intersect "stabily" the gear that depends (I suppose) from governor (B in the photo). A photo is here. The little gear (A, bronze, on right) is mounted on the spindle. The spindle can be mobilized very very easily.
Re: A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 2:09 pm
by phonogfp
If possible, let the motor run all the way down, then loosen the screw on the bronze gear (A) and move it slightly closer to gear B. Lubricate these gears with grease or Vaseline.
George P.
Re: A noise with a frequency equal to rpm.
Posted: Tue Oct 15, 2013 6:49 pm
by Henry
The pitch is "d", more or less, which in that octave would have a frequency of c. 73hz @ a'=440. Is the tt running slow?
Re: A noise with a frequency equal to rpm.
Posted: Wed Oct 16, 2013 1:15 pm
by doublemike
Re: A noise with a frequency equal to rpm.
Posted: Wed Oct 16, 2013 1:26 pm
by Henry
Henry wrote:The pitch is "d", more or less, which in that octave would have a frequency of c. 73hz @ a'=440. Is the tt running slow?
Disregard my post, above. Muddled thinking led me to compare hz (cycles per second, "cps") with rpm (revolutions per minute).
This is why I prefer "cps" to "hz". "Hz" tells you nothing, but "cps" *is* what it says.
Anyway, doublemike, I'm glad you solved your problem!
Re: A noise with a frequency equal to rpm.
Posted: Wed Oct 16, 2013 2:23 pm
by phonogfp
You're very welcome - - I'm glad all is well. I once had a gear loosen up on a similar motor and before I could fix it, it slid too far away from its meshing neighbor and suffered a "run." I then had two damaged gears to contend with.
George P.
Re: A noise with a frequency equal to rpm.
Posted: Wed Oct 16, 2013 3:26 pm
by doublemike
Henry wrote:Disregard my post, above. Muddled thinking led me to compare hz (cycles per second, "cps") with rpm (revolutions per minute).
This is why I prefer "cps" to "hz". "Hz" tells you nothing, but "cps" *is* what it says.
Anyway, doublemike, I'm glad you solved your problem!
Henry, I'm always muddled... ahahahah!
phonogfp wrote:...I once had a gear loosen up on a similar motor and before I could fix it, it slid too far away from its meshing neighbor...
Thanks, thanks and thanks more.
So, lubrication fixes loosen gears? This is interesting... I don't have to worry myself anymore for that alignement and for those gears, isn't it?