Hi everyone,
I am having trouble with my Fairchild 412 turntable. I replaced both belts, cleaned and oiled all bearings, but it is still running a little slow. Any ideas what I could do about that?
Thanks,
sev
I am having trouble with my Fairchild 412 turntable. I replaced both belts, cleaned and oiled all bearings, but it is still running a little slow. Any ideas what I could do about that?
Thanks,
sev
I have a Fairchild 412 (new belts etc) and it has the same problem as yours. Did you ever get it solved?Mine runs about 30RPM.
Do these use AC or DC motors? If DC it could be a simple matter of replacing whatever is used to adjust playback speed.
If a trimp pot was used it could have drifted or worn out over time and require tweaking. I do know that after time some trimmers can just fail. If the circuit fairchild used was fairly accurate anyway, then full rotation of the pot could alter the speed from say 30-36 RPM and was factory set before being sold. If the pot dies then it could default the biasing speed to 30. Much like a quiescent setting in an amp can change and sometimes kill an amp if poorly designed.
If its an AC motor then the speed is set by the frequency of the mains and is unlikely to change that much.
Not much to go on but just a thought.
If a trimp pot was used it could have drifted or worn out over time and require tweaking. I do know that after time some trimmers can just fail. If the circuit fairchild used was fairly accurate anyway, then full rotation of the pot could alter the speed from say 30-36 RPM and was factory set before being sold. If the pot dies then it could default the biasing speed to 30. Much like a quiescent setting in an amp can change and sometimes kill an amp if poorly designed.
If its an AC motor then the speed is set by the frequency of the mains and is unlikely to change that much.
Not much to go on but just a thought.
Fairchaild 412 Running Slow
I figured it out. The motor had to be taken apart (easy to do) and the pully shaft and well cleaned and oiled. That did it.
I figured it out. The motor had to be taken apart (easy to do) and the pully shaft and well cleaned and oiled. That did it.
Fairchild running fast
Same kind of issue here, my fairchild 412-2 runs a little fast.
I can't find any issues with the table, IM planning on replacing both belts. My Fairchild is a 2 speed and you can vary the speed slightly by turning the speed selector knob. But even with this it still runs aboout 34 rpm.
If all esle fails ill have the top pulley turned down slightly, or have a pulley made to a smaller size.
Same kind of issue here, my fairchild 412-2 runs a little fast.
I can't find any issues with the table, IM planning on replacing both belts. My Fairchild is a 2 speed and you can vary the speed slightly by turning the speed selector knob. But even with this it still runs aboout 34 rpm.
If all esle fails ill have the top pulley turned down slightly, or have a pulley made to a smaller size.
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