Restoring a Pioneer RT-909 Reel-to-Reel

[pustelniakr]

Recap Capstan Motor Drive Board

While the motor plate is removed, if you are going to recap the unit, now is the time to recap the capstan motor drive board. Replace all the 'lytic caps, refresh all the circuit board solder joints, and clean off all the old flux (isopropyl alcohol). Also, put fresh heatsink compound under the heatsink'd motor driver.

Pics 1 & 2 show 'before' and 'after' views of the capstan motor drive board.





Rich P

 

[pustelniakr]

Capstan Drive Work (cont)

1. Fill the bearing ball cups in the rear of each capstan shaft with white lithium grease, then push a nylon thrust bearing ball into each cup, to be retained by the lube (lube should overflow). Refer to pic 1.

​

2. Install a new capstan drive belt ( http://www.vintage-electronics.net/pioneer-rt-909-belt-kit.aspx ). It simply goes around the capstans as seen in pic 1.

3. Install the motor plate, with the motor pulley coming down on the top of the belt, as shown in pic 1. Secure the motor plate with its 4 screws.​

Rich P

 

[pustelniakr]

Reel Brake Work

While the brakes may work fairly well on these old units, the felt brake pads can be impregnated with lube and/or fine dust, and the brake pad adhesive can be quite weak. In order to ensure longevity after all this work, I strongly recommend replacing the brake pads (possibly available from fellow AKr, @jblmar)...

1. Remove the 4 screws (indicated in pic 1) securing the Control B mounting bracket to the front of the unit.

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2. Remove the single screw (indicated in pic 2) securing the Control B mounting bracket to the side of the unit.

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3. Remove the 2 screws (one at each end, on the back side) securing the top frame bracket, then rotate the Control B assy down, away from the reel motors, as indicated in pic 3.

​

I will show the process of replacing the more complicated of the 2 brake pads. The other one will be pretty much the same thing...

1. Remove the single screw securing the motion sensor slit (indicated in Pic 3), and remove the motion sensor slit. Then, remove the 2 screws retaining the motion sensor, and hang the sensor by its wire bundle (as in Pic 4).

​

2. Disconnect the brake spring from the motor assy.

3. Remove the c-clip and plastic washers ('A' in pic 4) from brake shaft. Be sure to capture both nylon washers (one one each side of the brake assy).

4. Remove 2 screws ('B' in pic 4) retaining the solenoid link to the brake, the slide the brake (& link) from the motor.

5. Mark the position of the brake drum on the motor shaft, then, loosen the setscrews retaining the brake drum to the motor shaft and remove the brake drum.

6. From the side of the unit, loosen the setscrews retaining the reel table to the front motor shaft and remove the reel table from the motor shaft.

7. Put 1-2 drops of Teflon lube (Tri-Flow, etc.) on each reel motor bushing (front and rear).

8. Reinstall the reel table, then, clean the brake drum braking surface with isopropyl alcohol and reinstall the brake drum.

9. Remove the brake band from its assy (2 screws). Carefully remove the old brake pad and its adhesive from the brake band. Be extremely careful in this process, not to bend or kink the brake band, or you will RUIN it. Please re-read what I just wrote. It is IMPERATIVE that you heed it!

10. Cut new pad to length with scissors & attach the new pad even with 1 side of the band. Then use a razor blade and trim the other side even with the band.

11. Reinstall the brake band, ensuring that it is square with its assy.

12. Lube the brake shaft with white lithium grease, install a nylon washer, then the brake assy (with its solenoid link), followed by another nylon washer and the c-clip. Then secure the solenoid link (2 screws).

13. Re-position the brake drum to center on the brake band.

14. Reinstall the motion sensor and the sensor slit.​

Rich P

 

[pustelniakr]

Recapping the Control B Assy

While the Control B assy is rotated down for access, if you are going to recap the unit, now is the time to recap the Control B board. Replace all the 'lytic caps, refresh all the circuit board solder joints, and clean off all the old flux (isopropyl alcohol). Also, put fresh heatsink compound under the heatsunk drivers.

Pics 1 & 2 show 'before' and 'after' views of the Control B board.





Rich P

 

[pustelniakr]

Torque Adjustments

The brake and motor torque adjustments are adequately covered in the service manual. However, here are a few considerations:

• Use a 7" reel with a hub diameter of 60mm, and a push-pull tension meter with a 0g - 500g range (such as: Chatillon DPP500G 500 g x 5 g (https://www.jlwinstruments.com/files/6613/3945/1916/Mechanical_Force_Gauge-DPP_SERIES.pdf)). Tie a string to the tension meter and wrap it in the direction of reel rotation opposite the torque being measured.
  
  
• Pic 1 shows how to simulate tape presence, so that the unit will attempt to drive tape. The frame front panel has tabs, intended to tie rubber bands to pull the tension roller guide pins off of their shut-off points.

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• Brake torques are adjusted via brake spring tension.
  
  
• Pic 2 shows the pots on the Control B board, for adjusting the various reel motor torques. The pots are clearly labeled on the board.

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• Brake torques should only be measured after the brake has been electrically lifted then freshly released (preferably, several times).

• Pic 3 shows the tension meter, wound for the following measurements: Secondary supply side brake torque

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• Pic 4 shows the tension meter, wound for the following measurements: Supply side brake torque, forward play back-torque, fast forward back-torque, reverse play take-up torque, rewind take-up torque.

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• Pic 5 shows the tension meter, wound for the following measurements: Take-up side brake torque, reverse play back torque, rewind back-torque, forward play take-up torque, fast forward take-up torque.

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• Pic 6 shows the tension meter, wound for the following measurements: secondary take-up side brake torque.

​

Rich P

 

[pustelniakr]

Counter Board Recap

The Counter board is accessed for recapping, by removing the 2 screws securing it to the front panel, and lifting it out of its retainer. Replace all the 'lytic caps, refresh all the circuit board solder joints, and clean off all the old flux (isopropyl alcohol).

Pics 1 & 2 show 'before' and 'after' views of the Counter board.




Rich P

 

[pustelniakr]

VU Drive Board Recap

The VU Drive board is accessed for recapping as follows:

1. Remove the single screw holding the drive board to the bottom of the frame.

2. Disconnect the connector to the VU Meter board.

3. Pull up on the Drive board, releasing it from the 3-pin connector on the Mother board.

4. Replace all the 'lytic caps, refresh all the circuit board solder joints, and clean off all the old flux (isopropyl alcohol).​

Pics 1 & 2 show 'before' and 'after' views of the VU Drive board.

Note: Leave the Drive board uninstalled while recapping the Mother board (next).





Rich P

 

[pustelniakr]

Mother Board Access

Now it gets really hairy/scary for a bit...

The Mother board is accessed for recapping as follows:

1. Remove the 2 screws securing the VU Meter & remove the VU assy (cable was connected to the Drive board).

2. Remove the grounding spring from the pitch pot ('B' in pic 1).

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3. Remove the panel nut and washer from each of the 3 level pots ('A' in pic 1).

4. Remove the 13 screws securing the lower chassis face (indicated in pic 1). Pic 2 shows the VU assy and lower chassis face removed.

​

5. Remove the ground screw ('A' in pic 3), the screw ('B' in pic 3) retaining the signal panel to the rear panel, the 2 screws ('C' in pic 3) securing the voltage selector to the rear panel, and the 3 screws ('D' in pic 3) retaining the lower rear panel. Then, remove the lower rear panel, as shown in pic 4.

​

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6. Remove the 2 screws ('A' in pic 4) to free the chassis to rotate open.
​

Rich P

 

[pustelniakr]

Mother Board Access (cont.)

1. Remove the screw ('A' in pic 1) securing the corner of the Control A board to the bottom right chassis side.

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2. Rotate the unit onto its right side.

3. Remove the 3 screws securing the left chassis side frame to the upper front chassis face.

4. Remove the screw securing the pre-amp board mounting frame to the left chassis side frame.

5. If the top rear frame brace is installed, remove the 2 screws retaining it to the frame and remove it.

6. Remove the screw securing the left chassis frame side to the chassis center brace, and remove the left chassis frame side, as seen in pic 2.

​

Rich P

 

[pustelniakr]

Mother Board Work

Now that you can access both sides of the Mother board, perform the following operations:

• Replace all the 'lytic caps
  
  
• Refresh all the circuit board solder joints (except those in thermal contact with any Styrol caps)
  
  
• Clean off all the old flux (isopropyl alcohol).
  
  
• Replace the old heatsink compound under all heatsink'd drivers.
  
  
• DeOxit all pots and switches on the mother board. Note: You will have to remove the shield from the 'REC Mode' switches before you can DeOxit them, remember to put the shield back on when done.
  
  
• DeOxit the contacts of the connector to the Control A board, then treat them with Pro-Gold.

Pics 1 and 2 show 'Before' and 'After' views of the Mother board...





Rich P

 

[pustelniakr]

Pre-Amp Board Work

While you have the Mother board accessible, the pre-amp board is also accessible. Remove the 2 screws securing the pre-amp mounting bracket, and maneuver the bracket free (twist latching tab), then perform the following operations on it:

• Replace all the 'lytic caps. Note that there are a few special low-leakage 'lytics (orange ones, replaceable by Xicon LLRL series).
  
  
• Refresh all the circuit board solder joints (except those in thermal contact with any styrol caps)
  
  
• Clean off all the old flux (isopropyl alcohol).

Pics 1 and 2 show 'Before' and 'After' views of the pre-amp board...





Rich P

 

[pustelniakr]

Control A Access & Work

1. Reassemble the left side, up to but not including the installation of the lower chassis faces (front and rear).

2. Rotate the unit onto its left side.

3. Remove the 2 screws (bottom) securing the Control A assy to the frame.

4. Remove the 2 screws securing the switch assy and switch array to the Control A riser.

5. Disconnect the 2 connectors from the Control A assy. DeOxit the contacts of each connector, then treat with Pro-Gold.

6. Protect the solder side of the Mother board, and hang the Control A assy for work, as in pic 1.​

Now that the Control A is accessible, perform the following operations on it:

• Replace all the 'lytic caps. Note that there are a few special low-leakage 'lytics (orange ones, replaceable by Xicon LLRL series).
  
  
• Refresh all the circuit board solder joints (except those in thermal contact with any Styrol caps)
  
  
• Clean off all the old flux (isopropyl alcohol).

Pics 1 and 2 show 'Before' and 'After' views of the Control A board...





Rich P

 

[pustelniakr]

Switch Assy Work

While the Control A Assy is accessible, the Switch assy is also accessible. Perform the following operations on it:

• Replace all the 'lytic caps. Note that there are a few special low-leakage 'lytics (orange ones, replaceable by Xicon LLRL series).
  
  
• Refresh all the circuit board solder joints (except those in thermal contact with any styrol caps).
  
  
• DeOxit the slide switches.
  
  
• Clean off all the old flux (isopropyl alcohol).
  
  
• DeOxit the contacts of both connectors, and treat them with Pro-Gold.

Pics 1 and 2 show 'Before' and 'After' views of the Switch assy...

Note: Do not DeOxit the snap dome switches of the Switch Array. DeOxit is not compatible with snap dome switches, and the only recourse to a faulty snap dome is replacement.





Rich P

 

[pustelniakr]

REC/PLAY Alignment/Calibration

Reassemble the unit, up to but not including installation of the cosmetic parts, faceplate, knobs and bonnet.

The REC/PLAY alignment/calibration of the unit is covered quite adequately in the service manual (head alignment, bias, EQ, levels, etc.). Here are a few considerations for this task:

• While working with the powered unit, be sure to wear adequate eye protection. 'lytic caps, installed backwards or over-voltage'd, tend to explode or go off like bottle rockets.
  
  
• While working with the powered unit, be sure to remove all conductive items from your hands and arms. There are some dangerous voltages in there.
  
  
• Before loading the very expensive calibration/alignment tape, run a few expendable tapes through, to make sure that the transport is assembled and operating correctly. Calibration tapes are over $100 each, so you really don't want to trash one.
  
  
• When it is time to put the calibration tape on, make sure you first thoroughly clean and demagnetize the transport. A magnetized transport will damage your calibration tape. I highly recommend a big Han-D-Mag de-magnetizer ( http://www.usrecordingmedia.com/handmagdebyr.html ).
  
  
• I know that folks fawn over the old Maxell tapes, but there are new tapes being manufactured today, which can be purchased at good prices. I highly recommend RMGI-Emtec LPR35 ( http://www.usrecordingmedia.com/1oprereta1.html ). It is a +6db tape with most excellent results. Although it is a +6db tape, I do not recommend trying to record to the full +6db, as you are likely to saturate the heads rather than the tape. I would recommend recording to +4db, but not to mis-calibrate the VU meters to read 0db at +4db, as some do. Calibrate the meters to an accurate 0db level, but record to +4db on the meters.
  
  
• I highly recommend calibrating the unit to the tape you will actually record on. That way you have optimum response, period. That is also another good reason to use modern tape. With old tape, you never know what condition the tape is going to be in, and it is very hard to optimize the machine to allow for the wide variation you will get with old tapes.
  
  
• For a calibration tape, I highly recommend the MRL 21T204 ( http://www.usrecordingmedia.com/caltap.html ). It has all the tones you need for playback EQ adjustment, playback level adjustment, speed adjustment, and playback frequency response testing.
  
  
• The input signal is not listed in the service manual for the 'Level Meters 0db Adjustment'. It should be 1kHz at -10db (316mV). The input level is then adjusted for the correct internal voltage level, and the meters are then adjusted.

The following lists a few web sites for good info on R2R calibration/alignment:

• http://www.soundonsound.com/sos/1997_articles/may97/tapemaintenance.html
  
  
• http://home.flash.net/~mrltapes/mcknight_biasing.pdf
  
  
• http://www.usrecordingmedia.com/whcataareall.html

Rich P

 

[pustelniakr]

Cosmetic Detailing

Before putting on the knobs and panels, be sure to clean them up and polish them.

Do not use harsh chemicals on the brushed aluminum. Limit your chemicals to a soft toothbrush and dish soap (not dishwasher soap).

For polishing, I suggest a good quality automotive wax. I use Meguiar's 'Cleaner Wax'.

Good luck on your own machine. Be careful. The results can make you cry (one way or the other)...

Enjoy,
Rich P

 

[kerozene]

GReat tutorial, Rich! It makes me want to find one of these just to fix it...

 

[jleon92f]

Awesome Rich, Now that is the machine to Buy!
Thanks for the tour..
John.

 

[MOPARWIZ]

Let me start by saying that I am very pleased with the work Rich performed on the RT-909. I came to know Rich through another fellow Karma member aka Oldskool when looking for an RG-1. After contacting Rich, he set me up with a resto RG-1 that has been a great attribute to my listening experience.

The RT-909 that is posted happens to be one that I purchased on ebay. I had previously purchased a mint in the box RT-909, that works perfectly, but wanted one to match for dubbing purposes. I searched Ebay for RT-909's that were listed mint and that were cosmetically in really good shape and it didn't take long until I found what I thought I was looking for. I did the usual, asking the seller questions, etc. Finding that this particular one had been freshly serviced with new counter belt, and demag and head alignment. It even came with the invoice from the tech guy who had serviced it. This was one of the things that helped me make up my mind to bid and secure the deal.

I had asked the seller about shipping and was assured that the 909 would be double boxed, insured and the like. Finally the UPS truck showed up at my office, opened and styrofoam peanuts flying across the ground. I was mad as all get out, but none the less, signed for it anyhow, thinking to myself, that if something was wrong, that I could at least get my money back through the insurance I had purchased. I took the RT-909 and the remnants of the box into the shop and checked everything visible for damage. Nothing appeared to be scratched or dented and I proceeded to hook her up and give it a try. I put on a small reel of tape to find everything seemed to sound fine with no apparent problems. Into the back seat of the truck it went and home to where I hooked it back up to my system and begin to check it with some recordings I had made. After about ten minutes of playing, I noticed that it would start dragging, and it seemed to be making alot of heat, the reels were not spooling up straight and after rethreading tape numerous times and restarting, everything seemed to get worse. I noticed at this point that one of the pinch rollers was not turning when the 909 was in play, upon removing the cover, it was evident that one of the special washers that was to go between the allen machine screw and the roller itself, had been replaced with a homeade piece of plastic, that was binding the roller up. I removed it, and not having anything like what was needed, I trimmed the homeade washer to fit so it would not bind. I then hooked back up, rethreaded again only to find everything was still dragging and getting worse. I pulled out the receipt from the tech person that had supposedly serviced it before it was listed and found out that he was a TV repair man in Alabama. His number was on the ticket, so I decided to give him a call just to find out how he calibrated and aligned the heads etc. I found out, that this guy not only DID NOT have a service manual on the RT-909, but didn't even own a calibration tape. When I asked how he performed the operation, I was told "from years of experience".

Now I was really aggitated! The only thing I could think to do was to see who was available to fix this baby, one that I had to much invested in to just set aside at this point. Before I knew that Rich restored decks, I looked into trying to have the deck restored or repaired here in Texas. I found someone who did reel to reel resto work in the Houston area, only to be turned away simply because I did not purchase the deck from him.

Disgruntled at this point, I contacted a friend of mine, AKA oldskool, that told me Rich had done a cassette deck for him and that it was absolutely fantastic. I told him that I had purchased a RG-1 from Rich but had no idea that he did resto work on reel to reels. I contacted Rich and he told me not to panic, that vintage electronics often need repair and recaps and etc. Rich told me to send it to him, and he would fix it and man did he, my baby had more problems than ever, and Rich has brought her back to life with his talent and gift.

Rich took his time not only in restoring my RT-909, but emailing me often and giving me updates on the problems and the remedies for a proper resto job. The post Rich has left here detailing every step, tells it all. He took his time to make sure everything was perfect. I am grateful for tech men like Rich who put a labor of love into what they are doing, it makes the end product even better.

Excelent Job Rich!

Even though you are several hundred miles from Texas, word is spreading fast among the audiophiles in our area who are astounded with your work.

Thanks again Rich

I have the pic of the RT-909 from the listing on Ebay that I am going to try and attach to another post. Remember, looks can definatly be deceiving.

 

[pustelniakr]

The so called tech had not only lost one of the polyethelene washers from one pinch roller (thanks to ReelProSound for replacements, more to come on that later), but he had also lost both 4mm nylon thrust bearing balls from the rear of the capstan shafts. This caused the capstan flywheels to scrape on the mounting screws in the capstan motor plate, so he put washers to push the motor plate even farther back. This gave the capstans a full 1/4" of in-and-out thrust play. So, when you played a tape, the tape swam all over the place.

Literally no-one makes 4mm nylon (or any other non-metalic, I even looked for saphire) balls anymore. What I wound up doing was using 4mm chromium steel bearing balls, and covered the motor plate contact points with skived teflon (probably better than original now).

The prevous owner had obviously played the unit with the tape misthreaded for a very long time, which caused truly excessive head and guide wear. This machine would actually shear the edges of the tape off as it passed by, as well as shave off oxide, which it would deposit in little curly piles on the table, beneath the tension rollers

I did not include the special work in the DIY section of this thread, because that section is intended for general application.

Innumerable thanks go to the folks at Reel Pro Sound. After several emails requesting to buy polyethelene pinch roller washers from a parts unit or something, I was told, I can't sell you something small like that. Just give me your address and I will ship them out to you, FREE. That's the AK spirit, somebody should invite them in if they are not here already.

Enjoy,
Rich P

 

[MOPARWIZ]

Hopefully this attached

This is a pic of the RT-909 as it appeared on the ebay listing when I purchased it.

Like I stated previosly, looks can be decieving.