[S Clark]

I picked up a Denon DL-102 mono cartridge that I had hoped to put on a JVC QL-F6 turntable, but the standard counterweight won't compensate for a 13g cartridge.  The way I see it, I can have a new counterweight made, look for another turntable such as an old Rekokut or something similar.  I'm looking to keep the cost of this mono experiment to a few hundred dollars if possible.  Any thoughts, comments,recommendations, criticisms?

Scott

[2002ss335]

If you are not concerned about the look why not put some Blue-Tack on the counterweight and use it to hold something heavy enough to balance the DL-102.

Regards,
Todd

[S Clark]

That had occurred to me, and I have a supply of modeling clay.  I thought I'd throw it out here for discussion first.  I'm still pretty wet behind the ears when it comes to vinyl playback.  For a couple of decades, my vinyl was played on a BIC 980 with a Shure 91ed.  Then it sat for about 15 years.  I've been using the JVC  and a borrowed Technics SP-10 for a couple of years, and have collected enough old mono Mercurys to warrant an experiment with a mono cartridge.  Since I am kinda feeling my way around in the dark, I thought I'd ask before trying the modeling clay on the counterweight approach.

[Ericus Rex]

One thing you might be able to do, depending on the design of your arm, that wouldn't be visible from the front is to blue tack a giant washer onto the back of your counterweight.  The armtube would fit inside the hole of the washer and that should be plenty of weight to compensate for the heavy cart.

[sunnydaze]

Lead weight tape.  Wrap as much as you need around counterweight.   Cut it to size, both length and width.

1 inch = 1 gram    (1/2 inch wide)

http://www.tennis-warehouse.com/descpage-BLT.html

[S Clark]

One thing you might be able to do, depending on the design of your arm, that wouldn't be visible from the front is to blue tack a giant washer onto the back of your counterweight.  The armtube would fit inside the hole of the washer and that should be plenty of weight to compensate for the heavy cart.

This has given me an idea. If I took JVC counterweight and tapped and threaded two holes for pins to extend out the back, then drill washers to slide on.  The tonearm could be balanced for the stereo cartridge, and add customized washers to the back of the counterweight for mono, without having to move the counterweight and having to reset with a pressure gauge every time you played a mono record.  Would that work?

[2002ss335]

I would worry about the washers vibrating/resonating without any type of clay. That would screw up your tracking.

Regards,
Todd

[S Clark]

Good point.... I think I'll just use the clay, and if I like what I hear, start looking for vintage rig for mono. 
Thanks for all the input guys.

Scott

[Wayner]

I have successfully added weight to the counterweight by using a brass washer, held on to the back of counterweight with plasticlay. The clay is a great bonding compound and also isolates any vibration.

Wayner

[Berndt]

I'm using some wheel weight stuck onto my counterweight.

[Mitsuman]

Seems like that would change the resonant frequency considerably? 

[neobop]

Seems like that would change the resonant frequency considerably? 

Not as much as you might think. Moving the counterweight closer to the pivot actually reduces eff mass, probably more than the extra weight raises it.  The 102 is a low cu cart. It tracks at 3g +/- 1g.

I've used a screw type hose clamp to add about 13g to a counterweight. One thing not discussed is where this extra weight is applied. Depending on the height of the counterweight, it might be better to add the extra weight on the bottom of the counterweight to lower the center of gravity. Tracking might improve with an underslung weight, but it would also reduce eff mass.

[jimdgoulding]

Seems like that would change the resonant frequency considerably? 

I've used clay on an arm tube, but never a counterweight, to add some damping and it definitely can/will change something!  Just tonite I'm cleaning up and re-balancing a Micro Seiki BL-91 with a Sumiko high mass arm.  I need to properly set my old Koetsu Black in its' headshell before I can give it a go.  I had forgotten how heavy the BL-91 is.  Whew.  12lb platter and a very heavy tonearm mounting plate, too. 

[S Clark]

With a blob of clay stuck to the back of the counterweight, I got the Denon playing last night. I was feeling my way in the dark, as I couldn't find my stylus gauge, but with a recommended tracking weight of 3g +- 1g, I figured I couldn't miss too badlly. A new digital scale is on the way. In the meantime, the bass sounded muddy on a London ffrr of Prokovief's Lt. Kjie, but I'll continue to play around with mass and position to see how things change.

[dlaloum]

I don't know whether this applies on your arm but...

on my QL-Y5F, the counterweight internal diameter is the same as the SL1200... so I went and got myself a small collection of CW's - both heavier and lighter - which gives me a lot of flexibility.

Just check the inner diameter of the CW, and you may find that there is a wealth of alternate CW's out there!