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Re: Checking speed
Posted: Fri Aug 03, 2012 12:07 pm
by FloridaClay
Nat wrote:I'd be interested to know how people allow for/adjust for needle drag?
Just measure and adjust the speed while a record is playing.
Clay
Re: Checking speed
Posted: Fri Aug 03, 2012 12:14 pm
by Valecnik
Nat wrote:I'd be interested to know how people allow for/adjust for needle drag?
BW - I watched the largely very good made-for-TV movie "Nuremberg" last night. At one point Jackson's secretary (note that this takes place in German y in 1946) was "listening" to a Marlene Dietrich record, ostensibly issuing from a Diamond Disc machine. Hmmm.... Some one slipped up there!
I was quite surprised when I speed tested my machines, Vic V, Edisons A150, A250 and C19 that the governors do a pretty good job compensating for the needle drag. I adjusted to 78 or 80 just running the motor then dropped the needle and they did not slow down.
Re the movie, "Nuremberg" I've seen it and never noticed the DD machine. Which model? Diamond Disc machines are almost unheard of in continental Europe and, of course no Marlene Dietrich on DD anyway.
Re: Checking speed
Posted: Fri Aug 03, 2012 12:49 pm
by phonojim
I built a strobe illuminator using a neon lamp and 100K resistor which I enclosed in clear tubing at the end of a 6 foot cord. I use this often in servicing turntables and for setting speed on my Lenco variable speed turntables which don't have built-in strobes. However, with the Triumph I need more than this. I need the capability to continuously monitor the speed of various moving parts, both under load and free running and a strobe is not the best tool for this job. I will be ordering the tach from Amazon very soon.
In times past, you could depend on the fluorescent light over your bench for 60hz operation and your strobe disc would give an accurate reading. However now with electronic ballasts, you have no idea what frequency you are seeing, so you need a dedicated source of illumination for your strobe disc.
Jim
Note: most machines I have worked with will govern the speed quite accurately, even compensating for the extra load of the reproducer. However, I still like to tweak them under load just to be sure. Not that it really matters, though, when recording speeds were all over the map!
Re: Checking speed
Posted: Sat Aug 04, 2012 12:43 am
by Nat
Re the movie, "Nuremberg" I've seen it and never noticed the DD machine. Which model? Diamond Disc machines are almost unheard of in continental Europe and, of course no Marlene Dietrich on DD anyway.
I'm afraid I don't know the model. -- In addition, I can't imagine a DD in a luxury apartment in 1946...
Re: Checking speed
Posted: Tue Aug 07, 2012 10:04 pm
by Tinkerbell
Brad wrote:
A few hints:
- you will have to place a small piece of reflective tape on the record surface. I keep a playable, but not valuable 78, DD, 2 and 4 minute cylinder with said reflective tape so I have them ready when I need to test.
I do this exact same thing... and to think, people have been questioning what use there is for all of that old Hawaiian music!
