noddou Posted November 11, 2015 Posted November 11, 2015 Good evening everyone Wondering if anyone could put me onto a method or a device where as I can check the Platter RPMs I'm asking as startup is slow to increase, or is this a characteristic ? Takes little pressure to slow platter ( when running a cloth over before playing) Records for my hearing seem to sound ok ,but there are times when your sure its not quite right when listening. Granded I'm newish to repairing these record players , although i have an idea its the spindle bears or motor any checks i can do is much appreciated :)
tubularbells Posted November 11, 2015 Posted November 11, 2015 This is what im using. Super easy to use and very accurate. http://www.6moons.com/audioreviews/kab/speedstrobe.html
Pegasus Posted November 11, 2015 Posted November 11, 2015 Courtesy of Vinyl Engine. "If you got an android phone with led-flashlight, the app "strobily" might be helpful.It provides a flashing frequency of your choice, independent of your mains frequency, so any strobe marks can be used, corresponding to the frequency they are desired for.It will work with the platter marks or with a printed or any other strobe disk as well.Another anroid app "RPM calculator" shows the actual speed in digits. A phone with a gyroscope is necessary. Simply lay the phone on the platter in any position and start the platter." "Also, if you have an iPhone, you could check out an app called Turntabulator." But either way you need to use a strobe disc. You can download one (and print it out) from here http://www.vinylengine.com/strobe-discs.shtml
Guest Posted November 11, 2015 Posted November 11, 2015 Be aware if you use a conventional strobe disk and mains powered lighting that the mains frequency varies during the day. At peak load times (industry start up and dinner time) the main frequency typically slows by 1% or more, then in late morning and mid evening, the mains is sped up to 'catch up'. The deliberate speeding up is necessary to keep all synchronous clocks (mains powered clocks) running true to time. If you are using the mains frequency to calibrate speed, avoid those times and check the mains frequency to four digit accuracy, i.e. 50.00 Hz +/- 0.05 Hz
Guest Posted November 11, 2015 Posted November 11, 2015 (edited) Records for my hearing seem to sound ok ,but there are times when your sure its not quite right when listening. Granded I'm newish to repairing these record players , although i have an idea its the spindle bears or motor any checks i can do is much appreciated :) Many older turntables like BSRs, Garrards and other idler wheel types, or early Japanese belt drives have a large induction motor. In this type of motor the rotor is 'dragged' around at a speed that is a function of the mains frequency and the number of poles in the motor. In reality there is always some 'slippage' and the motor runs slightly slower than synchronously. Minimising friction in the motor bearings is critical for the motor to run to speed. For 30 year old turntables it is usually necessary to disassemble the motor and clean the rotor shaft with a tissue and isopropyl alcohol, and use a paper stemmed cotton tip to clean out the bearing cups, then re-lubricate with a light machine oil, e.g. sewing machine oil. I use a fully synthetic friction modified light oil that should last for a very long time without deterioration. When the motor is reassembled the rotor should revolve for a several seconds if you spin the shaft with your fingers. If it doesn't. the bearings might not be seated correctly in the bearing cups. Give the motor a few gentle taps to shift the bearings into place. The idler wheel may need to be treated with 'rubber restorer' (http://www.wagneronline.com.au/rubber-roller-restorer/service-aids/tools-test/rrr250-11453/6857/pd/) to restore its 'gripiness' and the inside of the platter should be cleaned to remove any traces of old rubber, oil and grease. Use a tiny drop of the same light oil on the idler wheel shaft. I actually use HP (high pressure differential) oil instead of grease on the main platter bearing and also use HP oil on the platter shaft, as it reduces bearing noise and rumble by preventing metal to metal contact. When reassembled, the turntable should now run very slightly fast. This is to overcome the friction caused when the stylus is in contact with the record groove. Edited November 11, 2015 by Guest
Citroen Posted November 12, 2015 Posted November 12, 2015 Get yourself one of these dt-2234c+ digital tachometer for about $15 VERY accurate, cheap and reliable.
noddou Posted November 12, 2015 Author Posted November 12, 2015 Thankyou everyone i'll be looking into each of the options and Johnmath's technical advice will not go astray ..Ty John Gezzz your got be glad your a member of Stereonet :D Cheers and best wishes to you all
Guest Runaway Posted November 12, 2015 Posted November 12, 2015 I use an app on my iPhone called "PlatterSpeed" which is free (you can buy added functions). It is provided by Dr. Feickert Analogue. Requires a test record with a signal of 3150 Hz. You turn on the app, play the test record and put the iPhone near a speaker while it tracks the change in frequency according to the speed. It records the chart over the period the test record signal is played, stores it and provides deviation figures. I find it useful as it reads the speed with a needle on a record. Also used the Turntabulator which is not free but gives me a headache as I try to read the iPhone while it is sitting on the spinning platter.
Owen Y Posted November 12, 2015 Posted November 12, 2015 (edited) Get yourself one of these dt-2234c+ digital tachometer for about $15 VERY accurate, cheap and reliable. Yup, accurate enough. Certainly easier than dragging out the strobe disc This device displays only 2 decimal digits (& only +/-0.05%+1 digit accuracy) - but given that most adults can perceive only ~0.5-1Hz pitch variation, TT hyper speed accuracy is actually unnecessary. Cheers, Owen Dark Lantern blog - http://darklanternforowen.wordpress.com/ Edited November 12, 2015 by Owen Y
eltech Posted November 12, 2015 Posted November 12, 2015 Good evening everyone I'm asking as startup is slow to increase, or is this a characteristic ? sounds like you need a new belt.
noddou Posted November 14, 2015 Author Posted November 14, 2015 Hi all yes i could very well need a new belt Eltech or a combination .... tho my main reason for asking was to find a method or device for checking, other than this deck but also i have a Dual 1219 and Technics SL1900 many thx to all that have replied
peter farrell Posted November 14, 2015 Posted November 14, 2015 Hi vinyl lovers, try this link http://www.ebay.com.au/itm/Handheld-LCD-Digital-Laser-Tachometer-RPM-Test-Small-Engine-Motor-Speed-Gauge-/360732853621?hash=item53fd5a8575:g:VhUAAMXQILVSJ-K~ I have a couple and they are great PF 1
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