record player question?
I have a realistic lab-240 turntable with auto return. The arm has a weight on the back that you can turn, this balances the arm. when i play a record (33 not so much a 45) the arm sweeps over the record. Is it the weight in the back that i have to get right to balance it or is it something else?
The weight on the back of the tone arm is used to set the pressure of the needle on the record. To do this, you put the needle in the tone arm on a special scale and adjust the weight to the proper amount as specified for the cartridge you have. Too little weight and the tone arm skips. Too much weight and you wear the record excessively. I imagine you can still find these little scales at some speciality shops. I haven’t looked for one in years and years. See if you can find a web site for the brand of cartridge you have to find the correct pressure.
That happens to mine once in a while. It could be unbalanced; did you dust lately or move the turntable? I usually try to pull the arm all the way out and then all the way back (gently) and that sometimes resets it.
THE WEIGHT ON THE BACK OF YOUR TURNTABLE IS NOT SET AT THE PROPER WEIGHT OR IT WOULD NOT SWEEP ACROSS THE RECORD. IT SOUNDS AS IF IT IS SET TO LIGHT, TO CHECK THIS,PLACE A COIN (NICKLE) ON THE TOP OF THE TONE ARM AND SEE IF IT STILL SWEEPS ACROSS THE RECORD.
The balance of the tone-arm depends upon two major factors:
1) the counterweight, as you have pointed out; and
2) the weight of the pick-up cartridge.
Adjust the counterweight so that it just balances the weight of the cartridge, and that should just about do it.
Since your turntable is a Realistic, the folks a Radio Shack should also be able to help.