[dkd7]

After hearing of a few users with their 301 MK2 at 1.25 or 1.4g yielding great results, I wanted to try these lower settings. However when I approached 1.3g or lower, the highs were starting to break up slightly so I knew I needed a more accurate gauge if I were to explore at the manufacturers minimums. The higher end scales are just out of my budget and I have a very accurate scale I use for reloading just waiting to be used.

I have been thinking of a way to use my Acculab VIC-123 for a VTF gauge and while I cannot get a reading from the tip of the stylus, I think it should be fairly accurate. The finger lift is just short of the distance to the stylus tip, I would guess that whatever reading I get will be slightly heavier than at the tip. There surely is a formula to calculate the difference based on length however I missed that day in class. 

So I grabbed a piece of poplar and a dowel, cut the dowel to just over 8" and bored a forstner bit about halfway into the plank. Gave me just enough height and yes, there was a slight case of sweaty palms having about $5 of wood hovering over the almost $350 worth of stylus, so I made absolutely sure it wasn't going to topple over.

I may try a fish hook later to lift the cart right at the same distance as the tip is from the pivot point, but this just a beta test. I bored a 2 1/2" hole under the scale and attached a piece of monofilament line to the under-hanging hook, looped both ends with a slip knot to fine tune the distance of the loops. I will prob have the kids paint it later but for now the painters tape keeps the legs tight and the table is level and sturdy. I zeroed the weight on the tonearm and it rested level with the stylus tip about 2mm above the record.




I let the unit warm up for about 30 min, then calibrated the scale to the set 100g weight.





I first had a record on the platter and kept the stylus about 1-2mm above the record...this took many times to get the line at the correct distance.



I then measured the weight with the counterweight at 1.4g, again...I want to say that the measured force at the tip should be slightly less than what i'm measuring since the lifting point is closer to the pivot. Nonetheless, the reading was about .08 higher than the counterweight scale.





 I moved it up to 1.5 and measured again. Appears that the adjustments are fairly linear and somewhat close.



I don't know how much the weight will change if I measure out another 3/8" but needless to say I'm curious.

[dkd7]

So the suspense was killin' me....I made a hook and suspended the cart at the same point of the stylus tip.



The results were surprising, I'd say the counterweight is fairly accurate, at least at 1.5g anyway.

[Wayner]

The accuracy of the counterweight scale certainly depends on the zero-balance accuracy when setting the scale of the counterweight to zero at zero balance. I too have a Technics SL12xx series and I am impressed at the accuracy of the counterweight scale. I have bought a digital scale from dealextreme that is proving to be very accurate: http://www.dealextreme.com/p/digital-precision-scale-with-leather-case-5g-max-0-01g-resolution-16269




Wayner

[Minn Mark]

Yep, Wayner's right.

I bought one of these little scales on his advice in a previous thread and just the other day did a checkup on my TT's (4). Three were right on, and the misbehavin' one needed the weight (VTF) dialed back a bit. Solved my problem- was getting some distorion but tracked OK. I've 'calibrated' mine with a shiny new penny...should be 2.50 g.  Great scale esp. for the price, unless you really, really (really??)  need 1/1000 g accuracy.

Mark

[BPoletti]

I've got one of those DealXtreme digital scales.  They do a very good job.  I've given several as gifts.  Nobody has had a problem with them, at least none have been reported.

I have experienced a little bit of a glitch sometimes.  Occasionally, the scale does not return to zero after checking a weight.  The unit only needs to be power cycled (turned off, then back on again) to get back to zero.  But the weight is accurate when the scales starts at zero.   

[BPoletti]

Yep, Wayner's right.

I bought one of these little scales on his advice in a previous thread and just the other day did a checkup on my TT's (4). Three were right on, and the misbehavin' one needed the weight (VTF) dialed back a bit. Solved my problem- was getting some distorion but tracked OK. I've 'calibrated' mine with a shiny new penny...should be 2.50 g.  Great scale esp. for the price, unless you really, really (really??)  need 1/1000 g accuracy.

Mark

That level of accuracy isn't necessary.  There is more unit-to-unit variability of suspensions and stylus mounting angle than is consistent with what that level of accuracy requires. 

[Wayner]

I have noticed on mine that the Dealextreme scale will occasionally read .03 grams after a couple of needle drops. I also turn it off and then back on and it will zero out itself. The one small flaw to an otherwise great scale bargain. A flaw that is easy to live with.

W