M70 tuning needle

Atomtan

Member (SA)
Oct 22, 2010
44
3
8
U.K.
Hi folks, thank you for your guidance so far. My box is back together and I am so pleased with it (except for one error I know I made..).

I tried to be so diligent with everything as this was the biggest tear down and service I have done.

When re-inserting the chassis into the front case, I moved the white tuner clip (on the strung pully system) to one side of the dial and then manually slid the silver pointer within the front case to what I hoped would be right place (to correspond with the white clip)...It looked okay (but I didn't test it enough). So when the box was pretty much assembled I tested everything which worked perfectly HOWEVER, the tuner moved back and forth one inch and then stopped solid.

I am happy to take it apart again, but don't want to do it if there is a process to the tuner needle assembly that I need to follow.

As always, any guidance gratefully received.
 

floyd

Member (SA)
Jan 9, 2022
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Maryland usa
You could just turn the dial all the way to the right then set the needle at 108 FM. Then move the dial to the left and make sure it lines up with 88 FM . the needle is probably in the wrong spot . the sometimes put a dab of glue on the string where the needle originally sat.
 

BoomboxLover48

Member (SA)
Dec 3, 2010
5,763
275
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Chicago, IL
You can see a mark on the string where the needle was originally placed. That is another way besides what Floyd mentioned above.
Make sure you didn't somehow interrupt the free movement of the string in its path over the pulleys. Be careful not the break any pulley axles.
 

H3NK3L

Member (SA)
Dec 17, 2020
159
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43
France
Had the same issue 1st time I took it apart and put it back together. Somehow putting the black needlepart all the way at the end and the white thingy all the way to the same end doesn't make them line up, the white thingy hits right next to the square opening in the black part (thus moving it for a little while than leaving it behind).

If your needle doesn't move and when you turn the tuner knob it does change stations there s only one thing to do... Open it up, if the white thing moved on the string put it back (on mine there were 2 blue dots where it s supposed to be),

When closing up, I put it frontaide down and tuner section towards me, so I could see if it went into the right spot.

Much like you the first time I was very careful to put the needlepart and the white thing all the way at one end... But somehow the black thing moves further on its "rail" than the white thingy.

Kept it all in place by hand, lifted it a bit so I could see the tuner dial from the front, and moved the tuner knob both directions to see if I got it right. Took me 2 trials.

Last time I had the tuner window off, I managed it with 90 degree hooked tweezers there is a slightly larger opening where one can slightly push the white thing back and slide the needle in front of it (not sure if that's proper procedure though, but worked for me, being quite careful only "pushing the white thingy ever so slightly and only sliding the black needlepart, not moving the white part.
 

Superduper

Member (SA)
On the M70, the tuning needle is not connected to the tuner string like a couple of members have noted. Instead, a nylon block is affixed to the tuner string (on the chassis) where one might assume the needle would be. Don't try to undo it, or glue it, you may ruin it. On the M70, the tuning needle is actually a stamped aluminum part that freely floats on a rail. The nylon block simply pushes the needle around. The nylon block is shaped to be captured by the stamped brackets on the backside of the needle. The needle itself floats on the front cabinet 1/2. When you assemble, the easiest thing to do is place it at either the 88 or 108 part of the dial, tune the dial string to one end or ther other, and carefully slide the chassis to mate them together. The best way to do this is to do it with both parts standing up. When you get close, you can peek into the gap on top to make sure they are lined up together. Once you have them together, close the cassette door to keep them from separating.

I suspect that you have something pinched. To fix, you'll just have to disassemble. I recommend that when you have the chassis mated to the front cabinet, ensure that the tuner knob runs all the way (in both directions) before final assembly.
 

Atomtan

Member (SA)
Oct 22, 2010
44
3
8
U.K.
Thank you all for your replies and guidance.

The kicker for me is I had a note on my checklist to check this when the chassis went back in, but I missed it in my haste to see if it worked properly !

To anyone reassembling in the future, don't rush.