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Pioneer CT-F950 CT-F1250 reel motor RXM-047 substitution

S

stelirem

Silver Pioneer Forever
Maybe someone can help me with this issue: I substituted the Pioneer RXM-047 take-up motor in a CT-F950 with a new one that fits very well, 12V nominal 2400 rpm but absorbing 140mA instead of 50mA of the original one.
The question is: the driving circuit of the motor can supply with no side-effects such a current load or should I put a 100ohm resistor in series with the motor?
A second question is that after the substitution when playing the cassette the rec mode sometimes goes on even if the relevant switch is not pressed. Incredibly it goes in Rec mode more often if the rec protection tag on the cassette is removed.:worried:
I suspect that for some reasons the higher current flow has some strange effect on other part of the circuit.
Hope someone can help me.
Regards
Stefano
 
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Hope this could be interesting for future knowledge.... I tried to put a resistor in series (100ohm) and it was interesting that the "auto rec" effect disappeared. On the other hand it appeared again when the motor was connected directly. For some strange effects if the driving current exceeds 100mA the deck goes on rec even if not pressed.
I am thinking about to design an external driving circuit for the motor in order to limit the current maybe using relays (I found 2 that have exactly 220 ohm and can resemble the original motor load)
If I will succeed I will inform the forum since the new motor I found on the market is very efficient and works very fine. In this case people having problems with take-up motor in CT-F800 up to 1250 could do the same.
Have a nice sunday!
Stefano
 
Hello Jan,
in an electronic spare parts store in Rome. I am sure it is common to find it on the internet. The question as said is that even if you find the right one (CCW, Voltage, dimension and distance of holes and shaft lenght) probably it would absorb more than 50mA of the original one.
Have you considered to rebuild the original motor. I did it with success
http://mail.audiokarma.org/forums/showthread.php?t=53981&highlight=ct-f1250+take+up
Find also specific references for RXM-047 specs.
http://www.fischerelektronik.com/CT-F1250.PDF
Should you have difficulties in finding the motor let me know.
Ciao/ Stefano
 
I cleaned the contacts within the motor and it has a new life on it. It now works very well. First you should clean the contacts (there are two contacts at the top of the inner motor and the axis should be cleared as well).
You have to be extremely carefull.

12V nominal is too low voltage rating for what it takes on ff and rev: about 16 v, you should change something on the circuit. And the play mode has a different voltage, so another measurement and modification may be made.

When My CT-F1250 had its motor dirty, I realized that more often the motor would stop when recording, as if the current flow to the motor had a drop when changing from play to record mode. Sometimes it didn't stop when recording, sometimes it stopped even in play mode. but many times I started playing a test tape and when I pressed "play + rec" to change to record, then the motor stopped because of the "dead spot".

So maybe yes, there's a relation between record mode and motor voltage or intensity.
 
Thank you for your reply. I also rebuilt the take-up motor for a CT-F1250 and it works great!. I have also one ct-f950 that I am using as a test bed to see if I can solve the question of the take up motor with a new one. As said the motor works very fine. It is rated 12V nominal up to 18V. Then when FF or Rew the 16V provided gives the right torque. The only question is that it takes to much current.
I am also thinking about to design a electronic circuit powered by the 24V provided by the power assembly in order to provide 12/16V indipendently of the original contro assembly but triggered by this latter.
Congratulations for your collection.
 
I have the same issue on a CT-F950, I also have the Service Manual but can't see how the supply current is derived.
anyway adding an emitter follower transistor driving the substitution motor would not be difficult.
I'm interested where to buy the substitution motor.
Christian
 
I have a CT-F950 with the same problem when it happened accidentally recording FF to Play. Change we Mabuchi motor for EG530AD-2B (which I took the speed controller) and the problem was and now works perfect. Regards
 
I know this thread is a year old but i got to ask, I also need a replacement motor for my 950, but I'm a little cofuse, will the EG530AD-2B work with the 950? any modifications to be done to the motor ot the cassette deck?
 
Well the question is, will the EG530AD-2B run in reverse without problems? It seems you can purchase clockwise and counterclockwise versions, so I'm thinking it cannot run in reverse. Which would make it suitable for the capstan motor, but not for the takeup reel.

Charles.
 
Hey, guys....

Thought that I would share this tidbit with all of you. I have been fighting the CT-F950/1250 take-up motor issue for a number of years. I have two 1250's and two 950's that have been unusable due to the take-up motors being dead. I had a fellow bring me a 950 to repair, it's problem being that one of the plastic retaining clips for the cassette retainer, which is part of the transport, had been broken off and the retainer could not stay in position. I bought a used 900 for parts, knowing that the 900 and 950 transports were the same. I found that someone had replaced the RXM-047A tale up motor with a unit made by Matsushita. I remembered way back to earlier Pioneer machines and seeing motors with Matsushita labels on them. Pioneer does not make their own motors, or most of their electrical and electronic components. They are made by other companies and they then put their Pioneer label with part number on it. Most of the label on the Matsushita motor was illegible, but the operating voltage of 13.2 vdc was readable. I knew that the RXM-047A ran at around +/- 12 to 13 vdc in fast forward or rewind and around 7 to 8 vdc in the take-up mode during playback. I did some scrounging on the Internet and came across the Matsushita MMT-8SF2LT, which is almost identical to the RXM-047A. The shaft is maybe 1/8" shorter, but that does not interfere with installation in the deck. Both conductors are in a jacket, one of them being a shield. The white insulated conductor connects to the blue conductor on the motor termination board and the shield connects to the purple conductor. Running current for the RXM-047 unloaded at 13 vdc is 32 ma and the Matsushita unit runs at 26 ma with the same voltage applied. I have installed one of these in one of my 1250's and it appears to be operating normally in all modes The motors that I purchased I found on eBay by entering Matsushita and the part number and picked them up for less than $10 each. They appear to be new-old stock and were manufactured about the same time that the RXM-047A was made.

I'm sending along a picture. Mounting is the same. Hope that this will be helpful. Hope that you all have a great and safe Holiday season.

Best regards.... Clyde Campbell, Jr. Altairc27trIMG_1573.JPG
 
Shoukry said:
It seems its harder to get Matsushita MMT-8SF2LT, than RXM-047, any other motor can do the job?
Click to expand...

This is the only motor that I have found that will operate properly as a direct replacement. I did find another source in Canada. Here is a link to that company and the motor....

13.2V Electrical DC Motor MMT-8SF-2LT MATSUSHITA (petronaftg.com)

When I found them on-line, I stocked up on them, as I work on these machines quite often. If you continue having trouble locating one, drop me a note and I can send you one that I have on-hand as a last option. Wish you well in your search....

Best regards.... Clyde
 
Really Appreciate it, I rebuilt the motor I have and its working fine so far, I ordered 7 motors from the site you sent me to keep them on-hand should someone needs one I just hope they come through, I ordered from a similar site and three weeks later no motors so I got my money back, again thanks Clyde
 
Hi guys, I am not finding any of the part numbers and the Canadian source that was mentioned doesn’t seem to work. I need this part for my ctf900 and would gladly pay above the actual cost I just want my baby running. Please help if you can, I’m in Calgary Canada thank you All in advance
Palffypete@gmail.com
 
Hello....

Please send me your address and I will get one of the spares that I purchased out to you. Don't worry about paying me for it, as I have plenty of them and I purchased them at a good price. I know how frustrating it can be when a key part of your stack doesn't work as it should. I'll be happy to help you get your machine up and healthy again. Looking forward to hearing from you soon.

Best regards....

Clyde Campbell, Jr. Altairc27tr
 
Hi Members! Clyde Campbell has sent me a motor for my deck, it is not yet here but en-route. I have to say, this was a beautiful surprise and thank you so much, Clyde!
The old motor in my deck has a bad coil, 2 of the coils read 40-50 ohms and the third is reading 416K. Goes without saying I could not get it working. However, this appears to be a very slightly used unit, has basically new brushes so I am happy to give it to anyone that just need the brushes. In addition, I also have 2 brand new MABUCHI EG530AD-2B motors on hand, and I can certainly help someone out if needed. I am not quite clear on the installation of the Mabuchi motor, (there was something mentioned about a 100ohm resistor), perhaps Clyde or someone with similar to his expertise can clear it up, but what I can say is that it is a direct fit in terms of shaft diameter and mounting holes. This shaft is also a tad shorter than the genuine motor had but it will still hold the pulley just fine. Feel free to message me if you need parts and anyone with firm answer on installing the Mabuchi motor please post your input. (if i could find a 1250 that just needs this motor I would love to up from my 900) Thank you very much, guys!
 
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