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RT 909 Playing Slow

e_just

e_just

Well-Known Member
Hey Gang
I recently acquired an RT 909 and I am trying to get it up and running. So far, I replaced the belt with a genuine pioneer belt and replaced the ball bearings on the capstan wheels. The 909 is now working but playing very slow and without a stable speed. I have been reading through the RT 909 restoration guide and plan on performing many of the steps necessary to get the 909 back to spec. Would anybody happen to know what is causing it to play so slow?
Thanks
Eric
 
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What shape are your pinch rollers in? What tape are you using and did you clean up the tape travel path before playing?
 
The pinch rollers seem to be fine. From what I read, they get soft and gummy over time, mine are still hard rubber. I have used two different tapes with the same effect, one is a 10" Maxell the other a 7" Burgess. I did not clean the tape travel path and am not sure how to do so.
 
In general on reel to reels.

Make sure that the brakes "let go" in play mode. Look for the brake solenoids and make sure they pull in in play mode.

For Pioneer RT series. There's a motor speed control board. Look for transistors mounted on a sheet of aluminum. Inspect the leads of these transistors for signs of cracked solder. This is kind of common on these machines.

And, of course, check the condition of the mechanical stuff. i.e. take off the capstan belt, spin the capstan, checking for smoothness and freedom. Manually activate (by hand) the brake solenoid and make sure the reels turn smooth and easily, etc.

I did have to replace the sealed ball bearings in the capstan motor once. That is pretty rare though.
 
Cleaning the tape travel path involves nothing more fancy than Isopropyl alcohol in 90% or better fineness. Also, did you clean/deoxit the motor speed switch and pitch control yet? Sometimes those controls will mess things up.

If you are following the restoration thread, i assume you have cleaned and re-oiled the capstan shafts as well?
 
Problem solved! I oiled the pinch roller arms with Tri Flow and cleaned the capstan wheels. The main culprit of the poor performance of my 909 was belt residue on the motor. I removed the motor and took off the pulley to find a sticky mess that I missed the first time around. Using an exacto knife and some isopropyl alcohol, I removed all the residue. I immediately knew that my problem was solved because the motor spun by hand much more freely.
I was happy to record some funk records last night:yes:
 
Numistrek09 said:
Glad to hear it is back to normal. Did you check the belt to see if any of that crud got smeared on it?
Click to expand...
Yeah the belt looks fine. I cleaned the capstan wheels and the par of the pulley that comes into contact with the belt. The problem spot was between the pulley and the motor itself.
 
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