Telefunken M5 tube

[sensor]

Hier hat Peter Ruhrberg schon mal was zu dem Thema geschrieben vielleicht hilft das weiter, upps wurde gerade von bitbrain2101 drauf aufmerksam gemacht das er den Beitrag von Peter hier schon verlinkt hatte.

https://tonbandforum.de/showthread.php?tid=15367

[Vladislav81]

Hello Manfred,

I've tried today. I've got the finest grit sandpaper I was able to, cut a small splice, set 30 ips speed without a tape and tried to polish the face of the pinch roller that contacts with tape. No effect! I repeated, accurately. No effect again. I've wet this surface with the isopropyl alcohol very nicely. Almost no effect. I've took away the headblock and tried to set it playing without it, but with the tape.

Here's what I've got:

https://disk.yandex.ru/i/wpS5HKR3ORLuPg

https://disk.yandex.ru/i/Ss9G1_6SBKv9fg

Then I've tried to thread the tape (50 microns) other way:

https://disk.yandex.ru/i/L8UF-RSkXAMe0Q

It caused an effect. Yes, the right tape tensioner oscillated, but much less. Here's the video with the headblock on:

https://disk.yandex.ru/i/vdPAOMPdxFfitg

Then I threaded the tape in the standard way and run the M5 through all the speeds to show how does it work after all that:

https://disk.yandex.ru/i/GAdPDIEzZl4RTA - 19.05 cm/s

https://disk.yandex.ru/i/O_taJgCQHpMgpQ - 38.1 cm/s

https://disk.yandex.ru/i/U-upHTQgJtApKA - 76.2 cm/s.

Regards Vladislav

[Magnettonmanni]

Hello Manfred,
I've tried today ... to polish the face of the pinch roller that contacts with tape. No effect! I repeated, accurately. No effect again.

Hello Vladislav,
I think you're wrong about that.
The pinch roller looks to me like it's almost in new condition. You did that very well!

Congratulations

I also have to say that the mechanical adjustment of the tape path is still excellent.  This can be seen from the fact that the tape runs at the correct height without the headblock and does not move up or down, even though the brake on the right winding plate is just doing silly nonsense.

Your films are excellent.


To the matter of the error

First of all:
The right feeler lever must not move. 
It must be mechanically pushed inward in the play or record mode by the lever linkage (compare positions 5 and 6 in the illustration) to release the brake band.
Look at Page 9, third Paragraph of the service-manual. (I recommended in post #9)

   

Second part:
The brake band is set far too tight now. 
It won't even release when the feeler lever points all the way in.
You have to relieve the brake band to diagnose the error and then carry out the correct adjustment according to the adjustment instructions.
Then you will have a very nice device.

If the adjustment of the right brake is not possible, the brake band may be wrinkled.


Please send a good resolution photo of your polished pinch roller.

Best Regards
Manfred

[sensor]

Der Wickel sollte ohne Einwirkung der Bremse mit ausreichend vielleicht etwas zu viel Bandspannung aufwickeln. Dann kann man mit der Bremse die Bandspannung regulieren.

vielleicht sollte man auch mal prüfen ob die Spannungen am Wickelmotor stimmen

Vielleicht dreht sich das Lager des Wickels nicht gleichmäßig und leicht

es gibt verschiedene Ursachen warum der Wickel so schwach aufwickelt 

animiert durch den Thread habe ich meine M5B/C? vor gekramt und nach ca. 7 Jahren ein Probelauf gemacht, erstaunlicherweise lief sie 

[Vladislav81]

Hello Manfred,

Here are the photos of the pinch roller of M5:

   

   

I cannot make the new photos of it because I gave it to specialists to renew the rubber.

Great recorder, Ulf! I see that you took off the pinch roller cover, too? Does the tape recorder work better without it?

Regards Vladislav

[Magnettonmanni]

Hello Vladislav,

If this pinch roller is from your device, then I can only say: the external shape is perfect and the pinch roller of your device ran perfectly.
My advice about sanding was only for cosmetic purposes on the pinch roller.


The pinch roller cannot produce the error in your device shown in the films.

However, the pinch roller has a strange discoloration. Where does the strange discoloration come from?



How does the specialist revise the pinch roller?  (This seems completely unnecessary to me but it would be interesting to know.)
Pay attention: 
If he removes material with the lathe and thus changes the diameter, the pinch roller lever must be readjusted. 
You may introduce a new source of error into your device before you have even eliminated the first error.

Please note:
The right brake on your device is completely misaligned or defective. 
That is the main problem above all others.

Best Regards
Manfred

[Magnettonmanni]

vielleicht sollte man auch mal prüfen ob die Spannungen am Wickelmotor stimmen

Vielleicht dreht sich das Lager des Wickels nicht gleichmäßig und leicht

Hallo Ulf,

der Wickelmotor und der Andruckrollenmagnet bekommen ihre Spannung über denselben Kontakt von der Wiedergabetaste, deshalb ist es sehr wahrscheinlich, daß die Spannung stimmt. Beide Teile arbeiten ja auch hinreichend. 

Wenn aber die rechte Bremse nach einer Reparatur bei Normallauf nicht mehr zupacken kann, wird auch der Wickel wieder fest werden. Selbst das vollständige Schwenken nach innen öffnet die Bremse hier ja nicht vollständig!!!

Vladislav hatte die Lager geprüft und keine Unregelmäßigkeiten festgestellt.

Bezogen auf die rechte Bremse, haben daran schon mindestens zwei "Spezialisten" gewerkelt, ohne das System vorher verinnerlicht zu haben; und so benimmt sich die Bremse ja auch.

Viele Grüße
Manfred

p.s.
Da hast Du aber ein sehr schönes Gerät gezeigt.

[Vladislav81]

Hello Manfred,

Thank you for an answer.

I have an important question for you. Should the right coaster rotate more tightly than the left coaster, even with the brake fully released?

As far as the pressure roller is concerned, it's a bit hardened from time. It is necessary to return the rubber it’s elasticity, at least approximately close to the original. Now it feels almost like stone, very tight.

I know nothing about the cause of the discoloration, it already has this color when I got it.

By the way, the playback and recording amplifiers have been adapted to the capabilities of modern tape. Can you please tell me if this is a common practice for M5 in Europe now? I am planning to make new recordings on M5.

What do you think of the other way of threading the tape on the right side? I know that this is incorrect, but the tape doesn’t oscillate when threaded this way, and it doesn’t have a negative audible effect (no wow). The winding quality is still far from perfect, though.

Will inform you on further work on this tape recorder.

Regards Vladislav

[Magnettonmanni]

Should the right coaster rotate more tightly than the left coaster, even with the brake fully released?

No, absolutely no!!! 

If the tape counter is difficult to move, you should remove the drive belt for the tape counter. You don't need that at all for a good recording. 

In a worst case scenario, it only interferes with perfect tape transport.

Pay attention:
In your device the right brake is not  fully released by the tension lever!!! 
That is a big mistake

As far as the pressure roller is concerned, it's a bit hardened from time. It is necessary to return the rubber it’s elasticity, at least approximately close to the original. Now it feels almost like stone, very tight.

Where did you get the information, that the pinch roller was elasticly, when it was new.?

I only know these pinch rollers hard. 

They are even absolutely new not as soft as those on normal home tape recorders. For this you need a little more contact pressure. 

And don't forget, they last over 50 years in perfect condition and tey could last the next 50 years.

By the way, the playback and recording amplifiers have been adapted to the capabilities of modern tape. Can you please tell me if this is a common practice for M5 in Europe now? I am planning to make new recordings on M5.

In my opinion you live in Europe, when you live in or near Moscow. 

I think, you mean 40 years ago in the music industry.

Then and now, for an important new recording, you have to calibrate the device's recording amplifier to exactly the tape on which you want to record later. For long concerts you need tapes from the same batch. This all applies to both old and new tapes.

What do you think of the other way of threading the tape on the right side? 

If David and Igor Oistrakh, Yehudi Menuhin and Jascha Heifetz, had performed together in Johann Sebastian Bach's 3rd Brandenburg Concerto in 1970 and I had only realized 10 seconds before recording that there is this error in my device, I would have done the same.

If there had been another hour, I would have quickly removed the brake band. You don't need that for a good recording. To rewind you can turn the tape from right to left and then wind fast forward. This just takes a little longer for the swap time. (5-10 seconds). During the recording session, you can stop the tape with your hand, if necessary.
.



It would be very nice if you reported about your further attempts and repairs here in the forum.


Best Regards

Manfred

[Vladislav81]

Hello Manfred,

First of all, thank you so much for your reply.

I’ve tried today to spin the right side coaster (don’t know how it’s exactly in English) and the one on the left side. Both with the AEG kerns, with the brakes fully released, tried with the right hand only. Felt no difference at all. With fully released brakes, both coasters rotates absolutely lightly.

I’ll try the pinch roller with the renewed rubber about the next Sunday.

I live in the town near Moscow.

As for the tapes: I mean that the new formulas are much more capable of the higher recording levels and much less distortion than the tapes of 50’s the M5 was originally designed for. My M5 was never updated for, say, SM 911 or PER 528 - for making the recordings on these types of tapes. Until now. Now the frequency response of my M5 goes from about 35 Hz to about 23 kHz at 15 ips.

Should I try to remove the brake band on the right side and see what it would give? If the tape wouldn’t oscillate then the problem is clearly with the brakes system.

By the way, I use to rewind all the newly recorded tapes back to their original cores only when I bring the tape recorder back to the facility where I keep tape recorders, tapes and vinyl records. So there's usually no rush to rewind.

Regards Vladislav

[Magnettonmanni]

As for the tapes: I mean that the new formulas are much more capable of the higher recording levels and much less distortion than the tapes of 50’s the M5 was originally designed for. My M5 was never updated for, say, SM 911 or PER 528 - for making the recordings on these types of tapes. Until now. Now the frequency response of my M5 goes from about 35 Hz to about 23 kHz at 15 ips.

The old lady M5 can play all studio tapes of the world market and re-record them at their optimal operating point. This device can even magnetize tapes from 1940 to nowadays. My special tip would be PER 528 if the recordings are to last for the next few years.

Should I try to remove the brake band on the right side and see what it would give? If the tape wouldn’t oscillate then the problem is clearly with the brakes system.

I think, it could be a first step in the story to solve the riddle.
Perhaps you will be able to loosen the right break completely without dismantling.

By the way, I use to rewind all the newly recorded tapes back to their original cores only when I bring the tape recorder back to the facility where I keep tape recorders, tapes and vinyl records. So there's usually no rush to rewind.

My given hint of stopping the tape by hand referred to imprtant recordsessions without a right brake.

Best Regardsd
Manfred

[Vladislav81]

Hello Manfred,

Thank you for your message. I'll try to completely release the right break.

When I was trying to move the spring in the brake system on the bar (the brake band is attached to it) from the lowest hole to the next hole (just to check if it would do something good; nope; I returned the spring to it's initial lower position), I saw a long oval cutout in the bar where the pin moves. I envision removing that bar from the pin, and proceeding from there as circumstances dictate. The thing is, I've never had to completely loosen, much less remove the brake band before. I don't know how to remove the whole brake system on the right side from the M5, because there are threads there, and I'm not sure if I'll be able to put them all back in the same order. Or I don't have to remove the complete system, but only the brakes band? In this case, how am I to keep the rest brake system within the M5? Should I attach the threads and everything that goes with them to the rear side of the upperside of the M5 using the adhesive tape?

That's starting to be quite funny.

What would you advise me to do?

I don't have a pinch roller by now, though, and I'll get it only by the next Sunday.

Regards Vladislav

[sensor]

so in etwa sollte sich der Wickel beim betätigen der Bremse verhalten, dann kann man davon ausgehen das die Bremse sich richtig löst 

[Vladislav81]

Hello Ulf,

Thank you so much for the video.

I'll record a similar video today.

Regards Vladislav

[Magnettonmanni]

... when I first got my M5 from technician it already has this problem. So I called the technician and asked how to readjust the tension system. He told me there's a adjustment shaft on the right side under the tensioner, and that I need to loosen the screw, rotate the metal stick-regulator clockwise or counterclockwise and see what that does. So, I... broke the regulator cord or what is it called. I brought the M5 to another technician, he repaired this cord. Because I wanted my M5 working.

Hello Vladislav,
actually all possible ways of finding the error have already appeared in this thread and we have to start again from the very beginning, or even earlier.
Can you still remember which part of the brake band control you were screwing on?
I suspect that you or one of the specialists have completely misadjusted the quick stop brake.
Well, we'll see

   

Best Regagrds

[Vladislav81]

Hello Manfred and Ulf,

And that's how does it work on MINE M5.



Notice a strange position of the right tensioner in the playback mode.

I was screwing on a part number 8.

Regards Vladislav

[sensor]

ein paar Bilder von Innen, bei der man den Zustand und die Lage des Bremsbandes sehen kann

ein paar Bilder wo man den Zustand des Bremsgestänges und der Federn sehen kann  

wie sieht die Bremsscheibe aus hat die eine verschmutzte oder beschädigte Stelle

mich und vielleicht auch andere User würde es interessieren wie eine M5 von Innen aussieht

so sieht das bei meiner M5B aus 

[Vladislav81]

Hello to all,

What do you think of indent of the right tensioner on my M5 in the playback mode? I cannot pull it fully out (i.e. right). I mean, it shouldn't be acting like that in this mode, should it?

Regards Vladislav

[Magnettonmanni]

Hello Vladislav,

The translation of your text makes no sense to me.

Please let us move forward in very small steps and you should write if you don't understand the meaning or can't or don't want to carry out the steps.

You had already tried hanging a spring in an upper hole on the brake and didn't notice any effect.
I think you were on the right path and unfortunately you didn't go any further.

Please completely unhook this spring and then run a tape and record a film.

The tape would then have to be wound up without a pressure roller. 

With a pressure roller, the oscillation should become smaller or disappear.

Best Regards

Manfred

[Vladislav81]

Hello Manfred,

Yesterday I've completely unhooked a spring (while being slightly electrocuted twice by the contacts of a nearby transformer; it's not so easy to do), but didn't have the time to make a film. So I'll try to make a movie today. Should I thread the tape through the tape tensioner on the right side?

Yes, when I've tried hanging this spring in an upper hole, it didn't get any better, because the tape didn't move at all. No rewind, no fast forward and no playback mode. The tension on the right side has become too great, because thus I've shortened (i.e. tightened) the break band.

The tape moves slowly without a pinch roller. I'll show it today.

Here is it:



Best regards
Vladislav

[Magnettonmanni]

Hello Vladislav,


after the third electric shock at the latest, you should make it the most important rule of all to completely disconnect the device from the mains!!!


If you value your health, please consider the rule before your third electric shock. That one could just be enough to give you heart fibrillation.
By the way, this is the most common cause of death for old master electricians, because they think they can withstand it and at some point they couldn't withstand it.


Now to the point of interrest:

I am very pleased that you are now somewhat willing to respond to my suggestions.

Under favorable circumstances we will then be able to isolate the error.
I am sure, at some point later you have to record a beautiful film like Peter Ruhrberg from your perfectly running machine.

You have a rare ability to always do exactly what does not solve the problem and then to say: There is no effect

-...-

When I was trying to move the spring in the brake system on the bar (the brake band is attached to it) from the lowest hole to the next hole (just to check if it would do something good; nope; I returned the spring to it's initial lower position),

That is not right.
And yesterday you wrote about several effects:

-...-

Yes, when I've tried hanging this spring in an upper hole, it didn't get any better, because the tape didn't move at all. No rewind, no fast forward and no playback mode. The tension on the right side has become too great,

This is right and a problem-solving observation. Keep on doing.


Please take a film like this and after 5 seconds move the right feeler lever inwards.
Please do nothing on the left side, the error is on the right side.

Best Regards
Manfred

[Vladislav81]

Hello Manfred, 

Here are the films:




Best regards 
Vladislav

---

And the second one:



Best regards 
Vladislav

[Magnettonmanni]

Hello Vladislav,

There it is again ...

Version Nr.2 
of the old problem: 

You have a rare ability to always do exactly what does not solve the problem and ...

...  leads to a sandy desert and off course I never had suggested.

Why did you run the tape outside the feeler lever in posting #70.
(The AEG designer was proud at that time to have turned the idea of the feeler levers into reality.
Now I'm an old man. 60 years ago I spoke to a colleague of the designer.)

Please take a film like this (posting #70) and after 5 seconds move the right feeler lever inwards.
Please do nothing on the left side, the error is on the right side.

Please use the device absolutely in the mode of posting #70 without the spring and without the pinch roller.

Best Regards
Manfred

[Vladislav81]

Hello Manfred, 

Here is it:



Best regards 
Vladislav

[Magnettonmanni]

Hello Vladislav!

It looks to me like the brake band has still contact to the brake disc.
Do you feel able to loosen or remove the connection to the brake cable and the quick stop brake so that the brake band no longer has contact with the brake disc?
You should document each of your crafting steps with a photo using your smartphone!

Maybe it's best that you first send pictures of the brake with the brake cable and the linkage for the quick stop brake.

it would be very nice, if you also send a new Photo of your renovated pinch roller.

Best Regards
Manfred

[Vladislav81]

Hello Manfred,

I couldn’t get the pinch roller renewed because the technician got unhealthy.

I’ve made a photo today. This is the stop mode.

May I remove the brake band completely and see what it would give?

Thank you so much.

Best regards 
Vladislav

[Magnettonmanni]

Hello Vladislav,

I believe that in order to remove the brake band you have to remove the drive belt first.
I suspect this is beyond your capabilities at this time.

It is better if you try to understand the quick-stop-brake triggered by the stop-button and then either relax it (1 or 5) or unscrew it (4). 
Please document every step with the camera.

Don't worry, you can't adjust anything, the right side of the tape drive is completely out of adjustment and has also a fault

Take your time, I won't be available for a few days.


Best Regards
Manfred

   

[sensor]

es sieht so aus als wenn die verbogene Feder in die benachbarte Feder eingehakt ist 

   


   

[Vladislav81]

Hello sensor,

It's true. Could you, please, be so kind to make a most detailed photo of how it should look in a well working M5?

Thank you
Kind regards
Vladislav

[bitbrain2101]

Hello Vladislav,

please look at the left reel brake and compare. There is no difference, but it is the mirror image.

Regards, Tobias

[Vladislav81]

Hello Tobias,

Thank you so much, will look today and will make photos. I'm very suspicious of this crumpled spring at the top. It was put there by a so-called technician who was restoring a tape recorder. And it certainly doesn't have to be crumpled!

Oh, by the way, maybe I should try to swap these top left and right springs?

UPD: I've decided to completely remove the right side brake band from the reel holder. I'm applying the photo of this very brake band.

   

As you can see it's OK.

The crumpled spring previously was on the TFK M5b. Once, while preparing to record in a concert hall, I was carrying a tape recorder and unintentionally lost the brake springs. All I had to do then was to find more or less suitable springs. I couldn't find one exactly like the original, so I found this dodgy spring. Then the technician put it into this tube M5, and from it he put the spring into the M5b. And the technician disorientated me by assuring me that everything was adjusted. In my humble opinion, nothing can be adjusted with such a spring.

The rest part of the tension system is still there. 

Then I made a few videos (films) of how does the right side work. It made a slight effect for the better.

https://disk.yandex.ru/i/fwwjGqPAIpmRIg - without the pinch roller, tape is on the tension arm.

https://disk.yandex.ru/i/oPlKMkKqesDJ3A -  without the pinch roller, tape is NOT on the tension arm.

https://disk.yandex.ru/i/YnWjU-0kG2u7kQ - with the pinch roller, tape is on the tension arm.

https://disk.yandex.ru/i/WY0g-to6qytFNg - with the pinch roller, tape is NOT on the tension arm.


The last two films shows how does the downside of the reel holder spin when it's absolutely free. I've decided to do these films because I've heard some kind of crunching sound while rotating this wheel by the finger. I don't know for shure how should it rotate, with or without this sound. It could be the sound of the oil in the bearing, or it could be a bad bearing. I hope you would be able to hear this sound.

https://disk.yandex.ru/i/TloQHzRlaruVoQ

https://disk.yandex.ru/i/DmuONjw8AtoZwg


You may watch these videos as long as you need, I don't have to delete them. It's great that Yandex Disk is available in the European Union.

Regards, Vladislav

[bitbrain2101]

Hello Vladislav,

thank you for making the videos. What did you find out by comparing right side brake with left side brake ? Did you clean the surface where the brake band is threaded around ? I can still see the movement of the tension arm caused by an uneven rotation of something I can not see in the video. I can not hear anything in the last 2 videos, surroundig noise is too loud.

Regards, Tobias

[Vladislav81]

Hello Tobias,

There's almost no difference between the left and right sides, except an uneven rotation on the right side and the awful spring there.

Yes, I've cleaned the surface, but I wouldn't return the brake band to it's place because I need to bring the M5 to technician to change the bearings on the right side and all four rollers in the capstan drive section. I think I need to order it's production.

As for the crunching sound, I've clearly heard it. To my mind, the cause might be there.

Is it possible to remove the wind motor without affecting the fossilized wiring that's next to it, which could splinter?

Regards, Vladislav

[bitbrain2101]

I need to bring the M5 to technician to change the bearings on the right side and all four rollers in the capstan drive section.

Hello Vladislav,

if you are talking about the rollers in the capstan gearbox for the different tape speeds, there is nobody available in these days who can fix that. That is a very delicate task with difficult adjustments. I have never removed a M5 wind motor, so I can not answer that question.

Regards, Tobias

[Vladislav81]

Hello Tobias,

I want to say that I'll try to find a man who would produce these rollers from the start. I know a technician who could replace the rollers in the capstan gearbox.

To my mind, the reason for oscillation of the tape tensioner on the right side is in the poor condition of the bearings. That is, the bearing on the right side and the bearing in the winding motor.

Regards, Vladislav

[bitbrain2101]

Hello Vladislav,

there is no poor condition of the bearings. You did this video TFK M5 5.MOV and the wheel is spinning completely free without the brake band, so what ? If you want to replace parts from the gearbox, you will be walking on very thin ice as far as I know. Can you please take a video from playback mode with the headstack removed ?

If there is a real problem with the gearbox, I would try to get a M5A electrical switchable 2-speed capstan motor and install that.

Regards, Tobias

[Vladislav81]

Hello Tobias,

If the wheel spins completely free, then what is the cause for a bad working of the right side of the M5? Could it be the pinch roller?

Regards, Vladislav

[Frank Stegmeier]

Hallo,

ich habe diesen thread jetzt lange ignoriert, weil m.E. der Gaul von hinten aufgezäumt wird. Heute habe ich aus Langeweile ´mal wieder reingesehen und muß doch dazwischengrätschen. Ich bitte von vorne herein um Entschuldigung, wenn ich etwas überlesen habe und das längst passiert ist.

So wie ich das sehe, wird hier seitenlang über die Bremseneinstellung diskutiert (die inzwischen mit einiger Sicherheit völlig verstellt ist), statt dem korrekten Ablauf, wie er Manual beschrieben ist, zu folgen. Und das sieht nun einmal vor, daß die Bandzüge der rechten Seite nach Manual eingestellt werden. Und das wiederum geschieht mit den Schellen an den Widerständen hinten links, Anleitung siehe Bild.

   

Wenn die in Ordnung sind, kann man sich über die Bremsen unterhalten. Und dann müssen erst einmal brauchbare Bremsbänder her.

Viele Grüße

Frank

[Vladislav81]

Hello Frank,

Today I've tried to adjust the upper resistor. No effect. The only effect was when I've tried to move the clamp almost all leftside: after about a minute of working I saw a white smoke and felt, may I say, an odour. And the right reel holder didn't move at all.

I know I should't had to do that. But in order to understand that I should had to do that.

I think I'll try to adjust the lower resistors after I'll have the pinch roller renewed. I have a strong suspicion that the rubber of the pressure roller has become thoroughly hardened over time.

Best regards, Vladislav

[bitbrain2101]

Hallo Frank,

da man dich nicht anders kontaktieren kann nun auf diesem Wege. Bitte keine weiteren Ratschläge dieser Art ! Der Mann ist kein Techniker und hat im Betrieb den Schleifer des Hochlastwiderstands verschoben und dabei gab es Rauchzeichen. Das ist kontraproduktiv !

MfG, Tobias

[Vladislav81]

Hello Tobias,

No, it's OK, I understand I shouldn't have done that.

So, as for now, I see that the bearings at the right side and in the winding motor are OK. The upper resistor makes no effect. This means that the source of oscillations of the right side tape tensioner are not the bearings nor even the tension system. By now I think it's the pinch roller that become hardened and making the tape slipping. I'm being offered to renew the rubber on it, but I'm thinking of replacing it completely along with the bearing, to get rid of the problem for sure.

What does anyone think about this?

Best regards, Vladislav

[bitbrain2101]

Hello Vladislav,

you should look into the manual, how these resistors have to be adjusted. Do you know this abbrevation ? RTFM !!
As far as I can see, the upper resistor is for winding tension, not playback tension.

2. trial: Can you please take a video from playback mode with the headstack removed ?

Thank you, Tobias

[Vladislav81]

Hello Tobias,

Here are the videos of the M5's playing back without the headstack.

https://disk.yandex.ru/i/mDu6NBknODDNNg

https://disk.yandex.ru/i/u9K3zbax4S2Cyw

By the way, I think I've noticed that it works better when the headstack is removed.

Best regards, Vladislav

[bitbrain2101]

Hello Vladislav,

thanks for the Videos. There is nothing wrong with tape running at the capstan and pinch roller. Do you or your technican have a tool to measure tape tension ? Either the original Telefunken gauge or a Tentelometer ?

Regards, Tobias

[Vladislav81]

Hello Tobias,

The right tensioner still oscillates. Does that mean that the tape slightly slips? Or is it something else?

No, nobody in my neighborhood has tentelometer.

Best regards, Vladislav

[bitbrain2101]

Hello Vladislav,

tape slip was the reason, why I wanted to see tape travel without the headstack. I could not see any symptoms.

Regards, Tobias

[Vladislav81]

Hello Tobias,

With the headstack the tape slips.

Without the headstack the tape doesn't slip.

In either case the tape tensioner on the right side oscillates, only without the headstack it oscillates less.

Best regards, Vladislav

[bitbrain2101]

Hello Vladislav,

if you record a 1kHz Testtone and play it back, you should hear the tape slippage. Did you check that ?

Regards, Tobias

[Vladislav81]

Hello Tobias,

I'll check it today.

I just don't know how to use one channel for output to the M5 and the other channel for input back from M5. I use SSL 2 interface as an ADC.

I think I'll record a 1 kHz tone on M5 at 15 ips, then rewind the tape and digitize this recording. So I'll make two passes on M5, combining the wow and flutter first from the recording and secondly from the playing it back.

Best regards, Vladislav

P.S. So here is it: https://disk.yandex.ru/d/BaZkH32w-aMeSg

The tape used was EMTEC PER 528.

[Vladislav81]

Hello Tobias,

I cannot understand why does the tape slip. It slips at 30 ips even more than at 15 ips.

By the way, at 30 ips the PER 528 tape doesn't have time to wind up to the right side, and the tape winds on a capstan. Other tape doesn't do this. I think it's due to the protective back coating.

I don't understand why the tape does not slip without the head block.

Best regards, Vladislav