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Pioneer rt-707

Discussion in 'Tape' started by vendo81, May 12, 2018.

  1. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,804
    Location:
    California
    Lately I've been recapping and rebuilding my Revox PR99 MKIII reel to reel that I've used for several years. It's a great machine for recording on open reel.

    Many years ago I had a Pioneer RT-707 that I really enjoyed. Very compact and the sound was fantastic. I had bought dozens of prerecorded tapes which I still have. Unfortunately the reel to reel had developed a problem and years ago I sold it. I always wish I had kept it. My Revox is a 2 track and only plays at 7 1/2 and 15 IPS so the prerecorded tapes were just stored away.

    The other day I bought this RT-707 locally. I was very interested not only because of the great price, but it had very little use and not a single scratch on the face.

    I bought it from a person who was cleaning out his father's estate. He remembers him using it for a very short time and then replacing it with a large reel machine. He had forgotten about it until he went through a closet in his fathers house. It was in the original box, packing and plastic and had sat for decades. The heads look brand new. The insides and all metal work look brand new as it was stored in it's large heavy original plastic bag. There wasn't even any dust on it inside or out! Everything works except for the counter, which I'm guessing needs a new belt. Unfortunately the person threw out the original box last week as it had a tear on one side! I did get the packing and plastic protective cover. I even offered to go through his recycle trash for the box but it had gone 2 days before I bought it. There are a couple other items such as a metal reel, owners manual and accessories that he's going to send me as he misplaced them in the confusion of emptying out the house.

    Only things I have done was to demag and clean the heads. Because the playback recordings sound as good as the source, I'm going to wait to do any recapping and only replace any capacitors that have to be changed. I'll remove the face plate and lube anything that moves when I change out the belt.

    Anyone have tips on what should be lubed and any caps that have to be changed out?

    RT707.jpg
     
    Last edited: May 12, 2018

     

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  2. Hajidub

    Hajidub Chihuahua/Pug = Chug Subscriber

    Messages:
    5,068
    Location:
    Colorado Springs, CO
    Heads and tape path should be cleaned well, I'd also deoxit all the push buttons (bottom ones are a pain sort of). No lube required, I think its all sealed direct drive. Counter belt is the only belt. Enjoy
     
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  3. Onebean

    Onebean AK Subscriber Subscriber

    Messages:
    874
    Location:
    Nebraska
    Nice grab Vendo! I'm a 707 fan, and it sounds like you got a good one. I'd give the tape path a good cleaning, along with a splash of deoxit, and run it. Sounds like your way more experienced than I am when it comes to working on these, but I posted a tutorial on the AK tape forum, on replacing the counter belt. Maybe it will help if you decide to replace the belt.

    Onebean
     
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  4. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,804
    Location:
    California
    Thanks to both of you for your answers!

    Onebean ... Yes I noticed your tutorial on the counter belt and I'm going to use it for replacing mine. Great way to do it!

    I demagnetized and cleaned the heads and tape path, and cleaned and lubricated the pinch roller. Not much to clean as I couldn't get anything on the cue tips, but I did it anyway.

    I did some recording last night and the recordings sound as good as the source when using 7 1/2 ips. Very nice. Listening to factory prerecorded tapes I notice a faint cross talk at the
    beginning of each side of the recordings. Sounds like bass notes but is very faint. This just may be normal with this 4 track recorder but I don't remember this on my first rt-707. I'll check to see if its a head alignment problem when I get a MRL calibration tape. I am going to pull the face plate and lube all moving parts later this week. I'll deoxit all controls as well.

    If anyone knows if there are any problematic caps that really should be replace please chime in. I'll do a full recap when I get time as I don't want two machines apart at the same time.
     
    Last edited: May 13, 2018
  5. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,804
    Location:
    California
    I'm really wanting to get the face plate off this Pioneer but I'll wait until I get the new belt I ordered. It is working so well that I'd like to get it in the house.

    Having one machine apart is bad but two could result in mixed up or lost parts:mad:

    I almost have the mechanical rebuilding done on the Revox. I'll do a full recap next. I did rebuild a B77 several years ago. Having done the B77 helps but it's nice to read the postings and talk with a person who has recently worked on a PR99. This is what makes this forum so nice!

    Here's a photo of the Revox. It was never professionally used so it's in very nice shape....
    20180509_174302.jpg
     
    Last edited: May 13, 2018
  6. GPS16

    GPS16 Well-Known Member

    Messages:
    692
    Location:
    UK Manchester
    Hi Vendo81,

    do a search on Threads from Smurfer77. He did a full recap and refurb on his.

    The Capstan Motor is territory I kept away from when I had a 707. The reel motors may need to be lubed with light machine oil (not 3 In 1). In the thread form Smurfer there is a photo of the reel motors. A small hole can clearly be seen where a syringe can place a few drops of oil. The back of the motors is easy accessible the front side takes a bit more care. Do NOT get any oil on the brake bands or the reel hubs where the bands sit. The bands use felt as the friction surface and any oil will "soak" in. Getting that out again will be a job and a half!!! I would put about 4 drops in each hole and let it soak for an hour or two. Repeat this 3 times. After this amount of time the felt around the bearings will be bone dry!!!

    From other threads and issues. The Record button must not be neglected during the cleaning process as speed issues result. Also clean the multi way connector from the Motor to the Capstan Servo PCB. This is also a known problem area for speed issues. Search on Burgerman.

    For capacitors, I would do the large ones (reservoirs) in the power supplies (C401, C404, C326, C327, C325,C322). There is one near to the Bias Osc which gives it a decay and not a switch off (C315). There are also 2 on the Rec Relays (C313 and C314) which "hold the Rec Mode until the Bias Osc has had time to decay. This stops the heads (Erase and Record) being magnetised. There is also an important one in the Solenoid Logic (C408). The solenoid coils are fed with a high "pull In" voltage which tails off after a short delay to reduce dissipation in the coils to stop them cooking.

    Those caps are either stressed or important to the correct operation in my estimation.

    Congratulations on the acquisition of a fine machine. If the heads are in fine fettle then so much the better.

    For your PR99 make sure you only use PDP65 on the Capstan Motor. It is a high Performance Synthetic which may not mix very well if any other oils are tried. The Capstan Motor is the "Heart" of a high performance recorder. Without the mechanical performance, the quality of the electronics means diddly. Wow and Flutter failure will kill it stone dead. Don't "Spoil The Ship For A Ha'peth Of Tar"!! Those motors are proper Swiss Engineered units whether the machine comes from Loffingen or not. As you have the machine in bits, are you replacing the roller bearings in the reel motors too!!?

    Cheers.

    GPS16
     
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  7. nbndtrain

    nbndtrain Active Member

    Messages:
    451
    Location:
    Denver, CO
    DeOxit the Tape/Source button. You can easily lose a channel or two on that one.
     
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  8. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,804
    Location:
    California
    I will, and I'm also going to deoxit all controls...thanks!
     
  9. vendo81

    vendo81 AK Subscriber Subscriber

    Messages:
    1,804
    Location:
    California
    Thank you for the detailed reply!

    Smurfer77 is the person I've been talking with on my PR99. He was very detailed with his restorations on both the PR99 and his RT-707 and is a very helpful person. I would also like to contact you regarding some calibration questions I'll be having if you don't mind. Your extensive knowledge on these machines is a great help to many.

    Lucky for me the RT-707 is working perfectly. Every button works, the transport is solid and quick and the brakes are working like new. The speed control works great as well. The counter still works but the belt is slipping so I ordered a new belt. I will replace all caps you mentioned before putting it into service. I've just wrapped it back up in it's packing until I get the PR99 out of the way.

    I did order PDP65 from a person in Europe and I've been waiting for it. I've used no other type of oil on the machine's capstan or reel motors and they are as when new. I did order new bearings for the reel motors as well. I don't notice any noise, or feel any play but I'm sure it can't hurt to replace them. This PR99 was owned by a relative, and only saw home use so it hasn't had a hard working life. It's worked fine the few years I've owned it but it has never been serviced since new.

    Here is a photo of the heads on my RT-707 before cleaning. I looked close and don't see much wear and unlike my PR99, the tape guides show no wear at all.

    rt707 2.jpg
     
  10. GPS16

    GPS16 Well-Known Member

    Messages:
    692
    Location:
    UK Manchester
    Hi Vendo81,

    feel free to PM me. I don't mind. I still PM with Smurfer on a regular basis. A nice guy!!!

    I have a few Reel to Reels in my possession, 5 are Revox machines. I do have a NS 4 Track NAB B77 which I got as a replacement for a RT-707 which I bought from new in 1979 and wore it out. The heads were shot when I let a fellow AKer have it for spares for his.

    I am familiar with the innerds of the B77 as well as A700 and C270 machines. So where I can assist on your PR99 I will.

    My reel to reels are now getting a lot of use as there is now not much on the TV which is of interest. I am getting into the grumpy old man scenario!!! Such is life!!

    Keep us posted on your progress.

    Cheers.

    GPS16
     
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