Pioneer CT-50R

[Gepetto]

Amazing how these posts just keep on helping folks bring vintage gear back to life...kudos.

 

[cacharral]

Hi and welcome to Phoenix, the switch is on the bottom left of the mechanism.
You will need to pry it open and clean the contacts.
Also check the solder joints as they tend to crack.

Hi @20tajk7
Wow! Switch and contacts cleaned.! And the joints are re-solded too.
So, solved!
Now, the autoreverse mechanism is absolutely reliable. I am very grateful, @20tajk7 , I play tapes again, the analogic sound of this deck is amazing.
Thanks so much!

 

[laatsch55]

Far out, groovy and right on...

 

[20tajk7]

Well done ! Glad to see another CT-50R singing again.

 

[glastenbury]

I'm trying to bring my CT-50R back to life after sitting for years. I could use a little help. I've got a new capstan belt on it and play, fast forward and reverse all work but only for a few seconds. Exactly the same amount of time each time. This is both with and, without a tape in place. I have the manual but nothing jumps out at me except tape detection. Not sure that light sensor are working but I also think that is probably not the problem. Any suggestions? Thanks

 

[20tajk7]

Welcome to Phoenix and to the CT-50R club.
Is the tape counter running when you press forward play or fast forward ?

 

[glastenbury]

It was yesterday right afer I changed the capstan belt. It's pretty far apart now. The counter worked in Play in both directions but, I think I noted that it didn't turn in fast forward in either direction. 90% sure. Definitely worked in Play.

 

[20tajk7]

Well you need to replace the counter belt and the idler tire.

 

[glastenbury]

So, the counter stops the motors if there is slippage? Is that the only thing that does the protection job if mechanical failure is detected? I knew something did so I'm not at all suprised by your reply. Thanks!

 

[20tajk7]

1001 Hifi, a very cool site from an hifi collector.

The CT-50R was part of a new series of models introduced by Pioneer in 1983. This deck features an advanced auto-reverse mechanism with swivel record/play head. The micro-precision head holder is coated with a special lubricant lining so that the head housing will turn smoothly with little friction or play. In this model the tape quickly changes direction the moment an LED sensor detects the leader tape. This happens so quickly that almost no interruption in the music is noticeable. Also, when the MS/Skip switch is activated in the playback mode, if an unrecorded blank continues on the tape for 12 seconds or more, the tape deck will switch to the fast forward or rewind mode, until it detects the beginning of the next program. Track skip is also possible with the MS (music search) activated. All these logic-controlled functions are made possible by the use of Pioneers own PD4035 CMOS-IC. The mechanism is a 2-motor drive system (RYM-164) with one DC servo capstan motor (belt drive) and one DC reel motor with Hard Permalloy heads. Wow and Flutter is specified at 0.038% according to WRMS standard and 0.16% according to DIN standard. Frequency response is 25-17000/17000/18000Hz (normal/chrome/Metal) -20dB recording. The deck is equipped with both Dolby B and C noise reduction systems. On the right side of the front panel, we can find the headphone and microphone sockets while at the back panel there is a remote-control socket for the additional JT-217 cable remote controller. The tape type selector is automatic with status LED for chrome and Metal tapes. Recording level is manually adjustable while the level meter consists of a display with 8LED/channel. Some of the green LED have a "cut" in the middle in order to make-it look like there are more elements. Overall, this deck has a solid inside and outside construction, the top cover even has a vibration absorbing material across the middle part.
Cover Photo Art: Space Age Love - Published December 15th 2022

 

[glastenbury]

So, the counter stops the motors if there is slippage? Is that the only thing that does the protection job if mechanical failure is detected? I knew something did so I'm not at all suprised by your reply. Thanks!

Still stuck on this issue where any play or fast forward works but stops after a few seconds. Fixed my tape end sensor led and tape counter turns when it should.
At the tape counter circuit wires connect to the main board I see a very small DC signal on thr orange wire that I think goes back to the IC so I think it is basically working. What is this signal supposed to be?

What functions or signals are normally being monitored that are used to allow the motor to run normally?

thank you!!

 

[20tajk7]

When tape is running a slow square signal is on the pin #2 of DN6838 hall sensor ic.
That ic has 12VDC supply between pins #1 & 3.
Also check R635 & D611, these goes to pin #23 of microcomputer (sensing pulse input).
Take a look at the service manual, there's some waveform and timing charts of different functions.

 

[Mayrel2015]

Hello greetings again, does anyone know the measurements of the idler tire? I need to replace it and I can't find the measurement or in the service manual, if someone can help me with this information please. Thanks again

 

[20tajk7]

Hello, as I remember it's 16x12x2mm, I'll check on my notes tonight.

 

[20tajk7]

Originally the tire is OD 16mm to 16.5mm, ID 12mm and TK 3mm, a 16.8 x 10.6 x 2.4mm works fine as a replacement.

 

[Mayrel2015]

Originally the tire is OD 16mm to 16.5mm, ID 12mm and TK 3mm, a 16.8 x 10.6 x 2.4mm works fine as a replacement.

Thank you very much my friend, this information is greatly appreciated, thank you God bless you.

 

[20tajk7]

Testing the 6th CT-50R, put a cassette in ff rew seems ok, it plays but speed is slow at start.
Thought it was the capstan belt but nope :

The most wtf 'repair' I ever came across, the capstan belt is like new.
A 7805 installed in a strange way, the output (white blue wire) is connected to the motor negative lead and the ground (black wire) connected to the positive lead.

 

[20tajk7]

Don't know how that could have been worked.
So removed the 7805 and connected the wires in the right leads, white +12V, black ground.
Capstans spins in the opposite direction ! Wtf
Turned out the motor was a CW instead of CCW !

 

[20tajk7]

Put a new motor runing in the right direction, had to replace the pulley as it was bent during the previous 'repair'.
Lubricated the thrust position of the capstans, added the lost oil stopper washers.
Cleaned the idler tire and the pinch rollers.

Also added several screws that were lost.
Works much better now.

 

[20tajk7]

Pretty good wow & flutter, 0.06% (originally 0.045%).

Thanks again to Lee for this very useful unit.