Dual 1246 2x anti-resonator help

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realtv123
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Dual 1246 2x anti-resonator help

Post by realtv123 » 17 Jan 2020 05:31

Hello all.

Im new to the world of turntables and have just acquired this dual 1246 fully automatic. It has an ortofon cartridge installed. Im trying to balance the counterweight to make the tonearm float so that i can then set the tracking force. I loosened the screw on the side that holds the weight in place and slowly twisted the counterweight to make the tonearm free float (or what i believe was free floating). Now when i twist the weight i gets to certain point where it feels like it cant go anymore. Am i doing things right? I don't want to touch it anymore without knowing what to do. If anyone can help me balance the tone arm and set the tracking force, i would be greatly appreciative. [/img]
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Tinkaroo
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Re: Dual 1246 2x anti-resonator help

Post by Tinkaroo » 17 Jan 2020 18:21

Welcome to VE and the Dual Forum!

The wheel on the side of the counterweight is for fine adjustment after the rough balance is done by sliding the weight forwards or back. The same question was asked on the 704 which uses the same counterweight.

viewtopic.php?f=37&t=109649

dualcan
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Re: Dual 1246 2x anti-resonator help

Post by dualcan » 17 Jan 2020 19:28

Hi,
I'm afraid this counterweight is most likely done for, unfortunately.
It is originally from the 704/721 high end series, which was available as an extra for these automatics.
As can be seen here:
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Yours is in the arm, upside down now, with the shaft right side up and that is where the problem lies.
With the shaft and weight in correct position, the locking spring tab keeps the complete weight from rotating (here shown upside down):
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but leaves the spring loaded weight:
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advance or retract on the shaft, by about 5 turns of the fine adjustment wheel:
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The initial rough adjustment is indeed by sliding the complete weight/shaft, once the side set screw is loosened:
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It would be the same procedure for your automatic 1246. The proper sequence for this counterbalance with the Anti resonance filtering, can be taken from either 704 or 721 owners manuals.
Check (very carefully) with the weight right side up, if the actual weight is still suspended as in my second pic. That pic shows the weight's slanted heel up, because it is laying on the side, not right side up. The weight needs to be "springy" and if that is the case there is a chance to get it recovered.
Next push down on the locking spring plate (Pic 1) as close as possible to the weight body. The spring plate has to be retracted into the shaft's slot as flat as possible. Now try to rotate the c.weights housing (not the weight nor the adjustment wheel ! )
If you can turn the weight body back properly onto the spring plate, half the battle is done. It is now a matter of resolving the damage to the weight body and spring plate, in order to keep the c.weight body from turning again. That might require disassembly of the weight, but first, post what you find from your investigation.
Hopefully it works out and can be fully fixed.
Regards,
k

realtv123
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Re: Dual 1246 2x anti-resonator help

Post by realtv123 » 17 Jan 2020 21:12

Thanks guys. Im unsure of how to tell if the anti resonator is broke.. Im pretty sure its not, but i could be wrong. The guy i got this table from got it referbed from
Horiatis76. I got the tone arm balanced to where i think it needs to be and turned the tracking and anti skate to 1.3. How do i know if the anti resonance is broken?

realtv123
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Re: Dual 1246 2x anti-resonator help

Post by realtv123 » 18 Jan 2020 04:30

Sorry for the double post. But i forgot to add pics.

Heres how i have it set now. The weight still looks to be in place. When i play a record, everything seems fine.
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Tinkaroo
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Re: Dual 1246 2x anti-resonator help

Post by Tinkaroo » 18 Jan 2020 11:02

The vertical alignment looks good, and if it balances out OK it should be fine.

The silver coloured sprung weight as it came from the factory has some springiness to it and won't just sit like a dead weight at the bottom of the housing. If it does it won't perform its function of anti resonance but it should work fine as a regular counterweight.

The bimetallic spring inside of these sometimes breaks down and it's not easily fixed. Sometimes the metal of the spring actually splits. There are a couple of people who claim to have repaired these but most people will pull their hair out trying to do so. #-o

DSJR
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Re: Dual 1246 2x anti-resonator help

Post by DSJR » 18 Jan 2020 12:04

Just to add - from new out of the box, *some* of these counterweight inserts didn't sit true and level. Yours does though, so take care with it :)

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