Sony CFS-V1 Flutter Issue

[cpt.shotwell]

I've been restoring a Sony CFS-V1 and have got it working perfectly... almost. it's a beautiful unit and hope I can get it back to 100%, but I'm facing a flutter issue that I haven't experienced before. I can't find a service manual for the unit, not sure if it was sold outside of Japan or not, so can't consult that unfortunately.

The issue occurs as I reach the latter parts of each tape side, as it gets closer to the end there appears a noticeable amount of flutter, like everything has had some fast vibrato applied to it. i'm familiar with wow & flutter basics and have done what I can in the past to mitigate them, but haven't experienced this before where the flutter appears towards the end of a tape and gets worse till I flip it. So as the supply reel empties and the take up spool fills up, the flutter worsens. I understand any part of the transport can affect wow & flutter, but am hoping there might be some more specific areas to look at given my specific problem. Appreciate any advice! Thanks

 

[hopey]

Could be take up torque. This can be adjusted by shortening the spring (cut a bit off) for the clutch, it's usually in the spool. I think this happens when the pinch roller is old and hard, you could replace this as well or resurface by mounting on a drill and do a burn out on sandpaper.

 

[cpt.shotwell]

Could be take up torque. This can be adjusted by shortening the spring (cut a bit off) for the clutch, it's usually in the spool. I think this happens when the pinch roller is old and hard, you could replace this as well or resurface by mounting on a drill and do a burn out on sandpaper.

thanks for the reply just got another chance to work on this. are you able to help me identify that spring? here's a photo of the tape mech with the top plate removed. i''ll post a photo of the back of the mechanism too if that's where i should be looking...

 

[cpt.shotwell]

Could be take up torque. This can be adjusted by shortening the spring (cut a bit off) for the clutch, it's usually in the spool. I think this happens when the pinch roller is old and hard, you could replace this as well or resurface by mounting on a drill and do a burn out on sandpaper.

wow well... appears i've found the problem. sorta kicking myself that i didn't check this sooner. it was the counter belt. it's attached to the supply reel and it was too tight i believe, probley causing some friction/resistance to the supply reel moving properly. without the counter belt it sounds perfect. huh.

well i appreciate your advice and will keep that in mind for the future. maybe i'll source a new belt but i can totally live without a working counter