Telefunken M5a
#1
Hello,

I want to lube the pinchroller but I am unable to remove the small aluminium shield (Schild).
Can someone help me with a description of how to remove the "shield" on the pinchroller? 

Also: I need some advice on how to lube the capstan, the reel spinners and the 2 motors.
 
Best regards.
Evert
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#2
Hallo Evert,

die Andruckrolle ist Kugelgelagert und diese Kugellager sind gekapselt.

Der Deckel wird abgeschraubt.


[Bild: dscf8879800i6a3z.jpg]
Gruß Ulf
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#3
Thank you for your advice.
Do I need a special device to unscrew the shield?
Or do I just turn the shield to the left with two fingers?
Is it possible to lube the the 'Kugellager'?
Best regards
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#4
den Deckel nach Links drehen, zum Beispiel mit so einer Zange 
https://www.amazon.de/Sprengringzange-Si...th=1&psc=1

man kann ein wenig dünnes Öl in die Lager sickern lassen, dadurch wird das fest gewordene Fett wieder geschmeidig, besser wäre neue Kugellager einsetzen
Gruß Ulf
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#5
Thank you very much. I will order one via ebay.
Can you also help me with a description on how to lube :
1) the "Rotor des Wickelmotors" 
2) the "Mitnehmerteller" 
3) The Leitrollen?
Best regards
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#6
wenn die Angeführten Gerätegruppen nicht kaputt sind würde ich da nicht dran schrauben, nachher hat man mehr Schaden als die Sache wehrt ist

die Leitrollen sind auch Kugelgelagert
Gruß Ulf
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#7
Thank for your advice.
Best regards
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#8
funktioniert Deine Maschine?
Gruß Ulf
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#9
Hello Evert,

the pinchroller and the other rollers and the reel-tables have all ball bearings, there is nothing to lube. If a ball-bearing makes noise, you have to replace the ball bearing. The only part that needs oil is the capstan motor. But therefore you have to unmount the capstan motor from the mechanical deck and then disassemble the capstan motor to get access to the sinter bearings. Sinter bearings need a special thin oil made for sinter bearings.

Best regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#10
Thanx Ulf and Tobias,

The Telefunken M5a has a problem. Most a the time he plays, but sometimes it doesn't.
The problems started after I opened the recorder to set the bias. I think it must be something in the relays (AW1 start?). A bad contact, a wire or something.
I cleaned all the metal contact points of the relays but the problem reoccured afterward. I am still trying to find the problem.

Can you also explain how to replace the ball bearings?

Best regards,
Evert
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#11
Hello Evert,

did you also clean the contacts of the transport pushbuttons ? Explaining the replacemant of a ball bearing is very difficult for me, it wont help.

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#12
Hello Tobias,
Do you mean the small pins of the contact plate of the relay under the play button? Or is there an other small contact to be cleaned?
Best regards
Evert
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#13
Hallo Evert,

wenn die M5 nicht spielt,

bleibt die Capstanwelle stehen?

zieht die Andruckrolle nicht an?

vielleicht könntest Du den Fehler genauer beschreiben
Gruß Ulf
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#14
Hello Evert,

yes, the contacts which get closed mechanical when you press one of the transport buttons. At a relay the contacts are closed by an actuating coil, that is different from a pushbutton contact.

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#15
Hello Ulf and Tobias,
The widing motor spins perfectly forward and backwards. The capstan motor works also.
But the pinchroller doesn't engage when I press the play or record button. 
I cleaned the pins of all the contact plates in the relay but the problem still reoccured.
Best regards,
Evert
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#16
Hello Evert,

can you read schematics ?

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#17
Hello Tobias,
No, I can't read schematics but I know someone who can.
Regards, 

Evert
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#18
Hello Evert,

I have uploaded the schematic here, link is active for 1 week. Does your M5a have a remote connector ? There is one shown in the schematic as an option named BU238. If there is a remote connector, you have to put a plug with a wire bridge to it. If there is no remote connector, there are still wires for the remote connector, they have to be soldered together. I mention this, because I had a problem in this area with a M5a. The pinch solenoid in the schematic is M 307 = Rollenmagnet. You can find it in the lower left corner of the schematic. Look for bridge rectifier GR233 in the power supply, check the voltage at C235.

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#19
Thanx Tobias.
I will let it check.
Best regards
Evert
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#20
wenn ich mich recht erinnere hatte meine auch Probleme mit den Relais
Gruß Ulf
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#21
Hello,
Thank you for your advice. The problem seems to be solved!
It looks as it were the pins of the remote connector. The pins of the connector were badly soldered together.
But there is still an other problem: there are small volume fluctuations now an then. The fluctuations are on the recordings. The volume drops a few decibels (+/- 3db) every 30 minutes or so. The problem occurs on both speeds: 38 cm/s (less) and 19cm/s (more frequently and more decibels I think). I demagnitised both heads and rolls and I changed the tape but this didn't solve the problem. Do you have any suggestions?
Best regards
Evert
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#22
Hello Evert,

congratulations for fixing the problem. For the new problem I suggest to monitor the audio signal and the bias signal near the output of the record amp with an oscilloscope during record. Then tap with a not so hard tool at the tubes, the metal canned relais and the componenrs of the record ampflifier and watch the oscilloscope.

Regards, Tobias

P.S. Did you pull the tubes and put them back for cleaning the tube pins ?
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#23
Hello Tobias,
No I didn't clean the tube pins. I will do this first.
Best regards
Evert

Tobias,
What is used to cleans the pins best? Kontakt 61, very fine sand paper,... ?
Best regards
Evert
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#24
I did however remove the tubes a couple of weeks ago as an inspection of the tubes. I didn't clean them. Could the removal of the tubes  have caused this problem? Best regards
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#25
vielleicht besteht ein Kontaktproblem
Gruß Ulf
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#26
Bei meiner M5 verursachten die Kohleeinstellregler die sporadischen Pegelsprünge bei Aufnahme.
Das sind ungekapselte Exemplare bei denen der Kontaktpimpel sporadisch den Übergangswiderstand zur Schleiferbahn ändert.

Und jetzt die Google translation:

On my M5, the carbon adjustment controls caused the sporadic level jumps when recording.
These are unencapsulated items in which the contact pimple sporadically changes the resistance to the wiper track.

Cheers Jan
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#27
Thanks Jan for your advice.
Is your Telefunken M5 a vacuum tube reel to reel recorder or a transistor recorder? Both are possible I think.
The control panels on a M5 transistor recorder are different from the control panels on a tube M5(a) recorder.
Best regards.
Evert
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#28
Hallo Jan,

das sind nicht die Kohlepimpel, die da Ärger machen, sondern der Metallring, auf dem das andere Ende des Schleifers gleitet. Das Metall ist rabenschwarz angelaufen, das bekommt man mit einem dünnen Glasfaserstift wieder blank.

MfG, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#29
Hello Evert,

what I wanted to say is that the pins get cleaned a little by pulling them out and put back in. For the cleaning of the tube pins I use a glass fiber pen. You can not harm anything pulling the tubes when it is done carefully. Look for the metal ring in the center of the adjustment pots, if it looks black, clean it with a thin glass fiber pen.

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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#30
Thanks Tobias.
I will buy a glass fiber pen and clean the pins and the metal rings of the adjustment pots.
Best regards
Evert
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#31
Tobias. Is this the black plate of the adjustment pot?

Best regards

Evert
[Bild: JRl+BAcrLaVbsbrUAAAAAElFTkSuQmCC]
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#32
No, it´s from the other side. The ring goes to middle soldering point of the pot, the wiper connection. Dont touch the carbon pins of the wiper, no cleaning of carbon with glass fiber pen, metal only !!! Take fotos of the wiper postions of the pots before you start cleaning, you have to turn the pots to different positions to get proper access. With the fotos you can turn the pots in "nearly" former position to avoid complete misalignment.

Regards, Tobias
Strom kann erst dann fliessen, wenn Spannung anliegt.
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