Jh-110C dancer arm question

[networkresearch]

First time on Tape Op boards!
I need some help. I know there is another thread like this, but not totally the same, so be gentle.
Does anyone know how to re-set the electronic dancer arm on a JH-110C? I foolishly tried to adjust it when working on the tape tension. The manual made it seem like you loosen the screw,and twist the magnet to adjust. Mine almost completely came apart. Why I did this....! Is the shaft a leaf spring or a clock spring?
The problem was i couldn't get the tension set to the manuals specs without the dancer arm being completely over to the left. I've read a few posts of how to make adjustments and will try again, but the dancer arm worries me.
Any suggestions?
Jonathan

[ladewd]

Setting this up is quite an art. It really depends on whether or not you screwed with the spring. If you just moved the magnet and arm, all you need to do is ensure the magnet travels over the large green inductor on the flutter damper board, when the dancer arm is in the center of its travel. In other words, with equal amounts of tape on both reels, and the tensions set correctly the arm with the magnet should ride over the center of the green inductor (looks like a big resistor) on the PC board. The dancer arm should be in the center of its travel. Get the magnet as close to the inductor as you can without it actually touching.

If you really messed things up, you'll need a tentelometer to ensure the tensions are correct. Then (with equal amounts of tape on both reels) adjust the spring so that the dancer arm is in the center of its travel. When you achieve this, make sure the magnet is over the inductor. Good luck with this. If you run into a jam, give Steve Sadler at Blevins Audio a call and he can walk you through it for a small fee.I believe it buys you excellent technical support over the phone for about a year. He and I worked together for years at MCI and helping folks over the phone was a big part of our job. Most of the time, we were able to help customers fix their own problems. He probably remembers much more than I do, since I have gone on to a different area in the electronics field.

CA

[networkresearch]

Thanks CA! After reading you're reply, I don't think I screwed it up too much, at least not the spring. I got it back to where I think it was originally and when I unplug it the dancer arm oscillates so it is working when plugged back in.
I have a tentelometer to measure the tension, my issue all started with not having enough, (or the right), amount of tension. With the dancer arm in the riding in the middle, I only measure 3 1/2 oz. from the supply side. I push the pinch roller away and can get it pretty even. But again nowhere near where the manual states the tension should be,(6 oz.).
After the holidays I might sign up with Steve Sadler. I recorded with it last week and it sounds great, I just wonder what issues I might encounter with it set up like this.

Thanks again,

Jonathan

[ladewd]

I'll check my manual when I get home, since when Sony took over MCI, everything was measured in grams not ounces. If I remember correctly, tensions should be measured on each side of the capstan and should be somewhere around 120 grams. This translates roughly to 4.3 ounces. On the 110, you don't measure the tension on the supply side of the headstack. Just on both sides of the capstan. If you measure it like this, you don't have to pull the pinch roller away from the tape to do take up tension. We only did that with 1" and 2" machines, since we measured the spring tension on the dancer arms. I'll be back later, after I take a peek in the manual.

Cary

[ladewd]

Jonathan,

In my 110C manual, its 5oz on each side of the capstan for 1/4" tape. What width tape are you using? Its 5 1/4oz for 1/2" and 5 3/4oz for a 1". You should only concern yourself with the tensions on both sides of the capstan.

I also noticed in the section before the tension adjustment you need to get a spring scale and set the dancer arm spring so that 4 oz of pull will land the dancer arm in the middle between the stops for a 1/4" machine (5 oz for a 1/2" machine and 6oz for a 1") . Did you check this? This will definitely influence where the dancer arm sits at the correct tension.

Cary