Tascam 388 Transport Issue - Video Posted

Your problem is on the tension adjustment. not properly set. Do you have a tentelometer ?. Follow instructions on section 1-9. see image attached.

388 tension.png
 
fgonza2 said:
Your problem is on the tension adjustment. not properly set. Do you have a tentelometer ?. Follow instructions on section 1-9. see image attached.

View attachment 73907
Click to expand...

I don't have one I'm afraid. Is there a way to adjust them without one? I have been trying, but getting FF/RR to work messes up the playback settings and vice versa. I can't seem to reach a middle ground.
 
Yes, you eyeball it vs. the tape tension rollers position.

The basic positional geometry looks fine, but one word of caution that may be relevant to your problem.

*****************
In the 388 manual the table denoting reel/servo adjustment pots,.... RW Tension (R206) and FF Tension (r105)are BACKWARD. A MISPRINT.
So, when you think you're adjusting FF tension, you're actually adjusting RW Tension, and vice versa.
*****************

This took me hours of T&E to determine. I even pencilled in the correct pot #'s in one of my manuals, but apparently not every copy. If you're adjusting FF when you think it's RW, and RW when you think it's FF, you'll basically never get it right. Take that from experience.

I think from the looks of your video you have things set up ok in a basic sense, and your problem can be adjusted out with more effort.

*******************************
SO, CORRECT ME IF I'M WRONG, BUT
FF Tension = R206
RW Tension = R105
*******************************
I'm going off memory, guys, but it's a pretty vivid memory when I discovered this pertinent misprint. Tascam manuals aren't prone to misprints, but this one got out there. If I could find my second copy of the manual, would show where I pencilled in the corrections. For now, just going off memory and intuition. Ok.

:spank::eek:;)
 
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OK, Let me back up and add....

Looking at the video again, I don't think the tension rollers are in the right positions, geometrically. Look at the manual diagram, or picture it if you will:

As far as correct tensioning without at tentelometer, the position of the tension rollers tell the story. The CENTERS of the R. and L. tension rollers should intersect with an imaginary line that's drawn across the BOTTOMS of the tach roller and idler roller, respectively. (SEE FIG 1-3-8, above). That, of course, is when Play motion is moving tape forward. That's the basic geometry that will give you proper tension. Set those and then get back to the FF/RW issue afterward.

I still believe your issues can be adjusted out.

:spank::eek:;)
 
when doing this adjustments make sure to advance the tape to the middle of the reel too. As suggested above that imaginary straight line in the center can get you there
 
Well, I have it working intermittently. FFwd works better than Rew. I did notice that I am not getting any back tension on the right reel when rewinding, so when it rewinds, it is simply relying on the reel to 'pull' the tape without back tension. When it does this, it naturally slow down to a halt when the tape load on the supply reel get to heavy.
I check the underside of the deck plate and everything is working as it should (brakes releasing, etc)

The only time the take up side apply's back tension is when I physically pull the tension arm down to just above the point when the machine shuts off the transport. Could it possibly be something other than tensions, maybe?

*I just rebuilt the reel motors and they are rock solid. So I am not considering them a problem.
 
the other option is that the brakes maybe rubbing the reel tables, or tape is sticky, is the transport all clean ? is the behavior the same with new tape ?.
 
Arrgh. I have had this issue on every 388 I have owned at one time or another.

Its not primarily a tension problem . Use R112 and R212 to move the servo arms up to about the midpoint. Use a plastic (not metal) screrw driver/trimmer. The clue for me was it ran at speed when you pushed the servo arm down. The arms should be near centered in the slots
 
So I thought I'd throw a question I have up on a related thread. I was wondering if anyone could help with tension arm adjustments. I have been able to get the tension arms into position in play mode, but I'm not sure what to do about FF and RR. Is there a way to do this without a tentelometer? Would I set the tape running about midway through a reel, fast-forward or rewind, then adjust the arms to the same place I would for playback, with the center of the arms aligned with the bottom of the rollers? When I FF the tension arm on the right is significantly higher, and when I RR the tension arm on the left is significantly higher, but it seems like maybe it should be this way?

The reason I'm trying to get it together is because I'm having some counter readout issues. It seems to count consistently when playing, but when I rewind, well hit RTZ, it always goes about 20 seconds or more past where I had actually had it set to zero, even though it returns to zero on the counter. I cleaned the bottom of the tach roller and the sensors underneath. One sensor has a tiny dot on it that doesn't come off when I rub it with a q-tip, but I can't tell if it is something on the sensor or just a slight inconsistency in the surface of the sensor. I don't really want to pick at the sensor and scratch it up. I'm waiting on some rubber cleaner to clean up the rollers, but in the meantime I thought I'd adjust the arms to see if that helps.
 
...

I'm not sure if I can answer your question directly, or even if I've mentioned this above in this thread, but something to beware of is the FF and RW pot controls are mislabelled in the manual. I discovered this mostly by T & E, and maybe contributing to you imbalance problem. (206/R105). I can't find my other copy of the 388 manual to verify, but I'm sure I've run into this issue.
:spank::eek:;)

OKAY: I've dug up and checked both my 388 manuals and can't find where I'd pencilled in a correction, however I remember this so well caus it sent me into loops for hours til I figured it out. Verify it yourself and correct me if I'm wrong. Thx.
 
Thanks for the heads up. I guess what I was trying to figure out about adjusting in FF and RR mode is if there's a way to eyeball it. Or is it just a matter of tinkering around with it until it seems to move the fastest/most efficient. I don't really have any issues with FF or RR, but thought I'd try to get them to the perfect spot, or at least the optimal spot. Maybe I should just let them be and adjust them if they start giving me problems?

On a side note - with the counter issue I was having I replaced the pinch roller and tach roller with ones I had on another machine and now the issues are entirely gone. So I'm not sure if it is a matter of treating the rubber on the originals. Can the rollers go bad? They seem to move freely, they just screw up the counter. Dang. Guess I'll wait on that Caig rubber treatment stuff.
 
Hi my FF was not working, and counter was not working in FF or in play. I fixed it by adjusting r212 very modestly, correcting position of tension rollers, and in correct position it is now spinning the footage roller. Only problem NOW is that FF is so terrifyingly fast that I'm scared to use it. I made a very very modest adjustment to r212. Anyone know what this crazy ff issue is? thanks so much!
 
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