Restoring a Pioneer RT-909 Reel-to-Reel

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Hello Rich, would you mind updating the Left Tension Roller Rebuild post by adding to step 3 or 4 that the alternate configuration (spring + washers instead of ball holder) exists? Might save someone a lot of confusion, wondering if someone was in there before and replaced parts.

I will say, I have 2 machines, one with the upper ball holders, and one with the spring+washers. I noticed that with the ball holders, after a full rebuild, the rollers wouldn't snap back in place well if you don't move it all the way to the locking position first. E.g. when rewinding and the tape runs out, the rollers only move about 30 degrees to the side with the micro-switch. After some tinkering, it appeared that the upper ball holder assembly was to blame for this; all other inspections match your description perfectly (thanks again for that, it was very helpful!).

I played around with the ball holder assembly. Adding a little less or more lithium grease. It had a little influence, but it was still not always good enough for the rollers to snap back to the home position and engage the micro-switch. I'm not sure why to be honest. The guide offers no resistance at this part. I suspect the return spring might have been stretched during disassembly, mostly the 'ears' by which you attach them to the posts. Anyways, after replacing the ball holders with the spring + washers, it works great.

On a related note, where would one order new springs? Do you all have a large collection of various types of springs, and pick ones that match the old one closest? Look up the specs and specifically buy exact replacements?
 
I will have to have a unit with the newer configuration in my hands, before I can update the thread accordingly, reliably. I will keep it in mind. As far as helping with your issue, all I can guess is that the assembles did not go back together correctly.

Rich P
 
I'm not suggesting a full alternative guide, but perhaps something as simple as mentioning that if the reader's assembly looks different at this point, be aware that there is a newer revision. At least it will tell someone that they don't have to worry about missing or poorly replaced parts. I did, and it was only months later that I discovered that it was, in fact, a legit change made by pioneer itself and not something that could cause issues. Just takes a little guesswork out of the equation.

I haven't noticed any changes in the assembly myself other than the spring + 2 washers replacing the upper ball guide and its 3 nylon balls and the (same?) spring. I'd say one should be able to replace one with the other if so inclined. If I'd hazard a guess I'd say the newer revision is better in the sense that it's less complex and less prone to functional degradation, the only thing it doesn't do is slight dampening of the last part of the trajectory where the guide snaps back to the home (microswitch) position. Which seems to me like a good thing but I'm no mechanical engineer by any means.
 
Rich-
Just wanted to reiterate what many have said already, Thank You for the fantastic writeup. My RT-909 has been sitting for a number of years, so I will be slowly and meticulously going through and checking for proper operation. My capstan belt and pinch rollers are in good condition, so I may try and play a tape first to verify function. I did blow out some dust out of the unit with low PSI from my air compressor, but a brief inspection of the PCB's looked to be OK. Any recommendations you might have before I attempt to play a tape and verify functionality? There was some black tape residue on the tape guides, but I cleaned it off with denatured alcohol fairly easily. I do not see any wear on the heads, and no obvious residue or corosion as viewed through my 5X Magnavisions. I did remove the head base by mistake, then immediately replaced it. The head mount screws weren't touched, so will the heads need to be realigned? I wouldn't think so, but I'm no expert. I appreciate your consideration and look forward to a reply at your convenience.

Greg
 
Rich-
Just wanted to reiterate what many have said already, Thank You for the fantastic writeup. My RT-909 has been sitting for a number of years, so I will be slowly and meticulously going through and checking for proper operation. My capstan belt and pinch rollers are in good condition, so I may try and play a tape first to verify function. I did blow out some dust out of the unit with low PSI from my air compressor, but a brief inspection of the PCB's looked to be OK. Any recommendations you might have before I attempt to play a tape and verify functionality? There was some black tape residue on the tape guides, but I cleaned it off with denatured alcohol fairly easily. I do not see any wear on the heads, and no obvious residue or corosion as viewed through my 5X Magnavisions. I did remove the head base by mistake, then immediately replaced it. The head mount screws weren't touched, so will the heads need to be realigned? I wouldn't think so, but I'm no expert. I appreciate your consideration and look forward to a reply at your convenience.

Greg
Your head alignment should be fine, as long as you did not move them within the head block.

Your tension rollers may be a bit stiff, and their internal tape presence sensor switches may be intermittent.

Good luck,
Rich P
 
Rich-
Per your restoration thread, I acquired some 10,000 AND 15,000 cSt silicone damping fluid. Does the Pioneer specification call for 10,000 cSt, or was that an approximation based on your professional opinion? I could find no reference to it in my service manual or the service bulletins.
Thanks,
Greg
 
I went to the local RC car shop and bought some of every weight. I have specified what worked correctly, and how to apply it.

Rich P
 
Well, I've completed most of the work in the restoration thread, and have capacitors on order after visually verifying every one for value, temperature, voltage, and orientation. I suspect I may have an early version RT-909, as it appears that some of the service bulletin information modifications have not been performed. At this late stage, Rich, would you recommend attempting performance of the applicable service bulletins, or just replace the electrolytic caps and have done with it?
Greg
 
Well, I've completed most of the work in the restoration thread, and have capacitors on order after visually verifying every one for value, temperature, voltage, and orientation. I suspect I may have an early version RT-909, as it appears that some of the service bulletin information modifications have not been performed. At this late stage, Rich, would you recommend attempting performance of the applicable service bulletins, or just replace the electrolytic caps and have done with it?
Greg
Your machine has survived all of this time as is. That would be what I would do. I would simply restore the machine you have to what it was originally, unless you are aware of a field mod that was a high priority.

Enjoy,
Rich P
 
One thing I did notice-when attempting to reposition the tape guides to a fresh bearing surface, I COULD NOT loosen two of the three hex head screws for the guides. I exerted enough force with a 2mm hex wrench to just barely start rounding, but quit before rounding them out. I then examined in detail the bearing surface of the guides in place and decided that I wasn't going to move them at all. Here are some pics of the heads and guides. If I recall correctly, the heads have about 200 hours on them max.

DSC00005.JPG DSC00006.JPG DSC00007.JPG
 
You will probably be alright. The guides generally have cut outs on the sides of the tape paths, to prevent the creation of wear grooves. As long as the guides are not too badly worn, I would not risk causing damage to rotate them.

Enjoy,
Rich P
 
You will probably be alright. The guides generally have cut outs on the sides of the tape paths, to prevent the creation of wear grooves. As long as the guides are not too badly worn, I would not risk causing damage to rotate them.

Enjoy,
Rich P
Hi Rich, I going to recap my RT-909 has been ordered complete (125 nos including reel motor caps) caps kit from eBay

I have question? as you said in this thread "DeOxit the contacts of each connector & switch, then treat with Pro-Gold! What is this pro-gold I can't googled? where do I can find. Is it some kind of lubrication. Thanks for your great thread. Rajkumar
 
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Hi anybody can help me? My RT-909 working as build perfect, I going to recap, I have reel motors caps 5uf 250V instead of 4.5uf 250V original. Can I replace them with 5uf? Thanks Raj
 
I have question to Rich P,
My RT-909 working perfect, no any issues. Now I'm doing recapping; when I recapping all switches need to be clean with Deoxit and treat pro gold? My switches & potentometers working good, I'm worry after clean may problem raise! How about potentiometers output, mic input and pitch controls need to clean by Deoxit and treat pro gold? Thanks for help Rajkumar
 
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