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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 28th Jun 2020, 3:16 pm   #1
wirralman
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Default Grundig TK18 Reel to Reel

I bought a Grundig TK18 reel to reel tape recorder which was received damaged (not surprised since it was very poorly packed for such a heavy item). It looked like it had been dropped on a corner.
Surprisingly, everything ( mechanical ) worked apart from the play button.
As these tape recorders are rare I did not want to give up on it and so I took the top off to see if there was any obvious internal damage. A drive belt had snapped. Length = 41cm.
I found a video on YouTube showing a TK14 being repaired for a drive belt but to the fast rewind. The video is very short on details however.
Could someone perhaps give me a little more help on how to fix the drive belt ( to the play capstan, not the fast rewind ). The author here says that the existing belt could be stuck back in one loop using super glue as spares are unavailable.
Of course there may be other problems with the recorder but I would like to try to get the play button working again at least before I abandon it.
I note that the TK14 has a valve at the front but there is no such valve in my TK18!
YouTube reference is: https://www.youtube.com/watch?v=ueRV8-c9FdI
And two photos of my acquisition are attached.
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Old 28th Jun 2020, 4:20 pm   #2
vidjoman
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Default Re: Grundig TK18 Reel to Reel

Quote:
Originally Posted by wirralman View Post
The author here says that the existing belt could be stuck back in one loop using super glue as spares are unavailable.
The original belt is unobtainable but replacement belts will be available - you need to work out the diameter and width and look online.
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Old 28th Jun 2020, 5:42 pm   #3
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Default Re: Grundig TK18 Reel to Reel

The valve at the front is an EM84 in this series of Grundig TK's and is called the "Magic Eye" and during recording the manual recording level is adjusted to achieve optimum recording level as shown on the EM84 display.

The TK18 & the De Luxe version TK18L only do automatic setting of the recording level (called "Magic Ear") therefore do not have the the EM84 valve.

David
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Old 28th Jun 2020, 5:53 pm   #4
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Default Re: Grundig TK18 Reel to Reel

Some people do successfully super glue belts back together, I think it works better with thicker belts, I have never done it myself.

The set of compatible belts are readily available from online sellers, more difficult to get a single belt. You can also buy large sets of miscellaneous sized belts where you might be lucky to find one that suits.

David
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Old 28th Jun 2020, 5:58 pm   #5
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Default Re: Grundig TK18 Reel to Reel

Quote:
Originally Posted by wirralman View Post
....I note that the TK14 has a valve at the front but there is no such valve in my TK18!....
There should be a lamp in your TK18 where the EM84 would be in the TK14, as the TK18 has Automatic record level control.
If you look at the top cover there should be a window with the word "Automatic" in it which is illuminated by the lamp during record mode.
There is no option for manual record level control on the TK18

David beat me to it whilst I was typing

Regards

Andrew
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Old 28th Jun 2020, 6:21 pm   #6
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Default Re: Grundig TK18 Reel to Reel

Replacing the flywheel drive belt is somewhat awkward I find.

Theoretically you can do it with the flywheel in-situ but I find it difficult, so I remove the flywheel for better access.

Main steps are:-

Tip - Take lots of photos during strip down to aid re-assembly.

1. Remove the 3 countersunk screws that secure the Sound channel plate (the plate that the heads are mounted to), note that the right hand screw also secures the top deck fixing bracket.

2. Carefully lift up the complete Sound Channel assembly and hinge over to the right side. To do this you first have to disconnect the Pause key linkage that connects to a lever on the top left of the Sound channel plate. Also have to disconnect the long metal lever that pushes the Pinch Roller forward, I do this by removing the single screw that secures the metal bracket that the end of the lever slides in.

3. At this stage you may if you are lucky be able to thread the new belt around the flywheel and up to the motor pulley, if not the flywheel then has to be lifted up, to do this you have to disconnect the long lever which is difficult to explain. I will try to explain it later today with some photos.

David
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Old 28th Jun 2020, 6:26 pm   #7
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Default Re: Grundig TK18 Reel to Reel

Quote:
Originally Posted by AndiiT View Post
If you look at the top cover there should be a window with the word "Automatic" in it which is illuminated by the lamp during record mode.
There is no option for manual record level control on the TK18
Is that what the 2 yellow wires are for ?

David
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Old 28th Jun 2020, 8:49 pm   #8
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Default Re: Grundig TK18 Reel to Reel

I was wrong about maybe having to remove the flywheel, this may only be necessary when replacing the clutch belt from the underside of the flywheel to the Take Up Reel Table.

So main steps for replacing the flywheel to motor pulley drive belt:-

Take photos during strip down to aid re-assembly, its quite easy but first time can be a little confusing.

1. Disconnect/isolate from the mains supply - keep safe.

2. Remove tape/spools & remove the top panel (4 screws) and then remove the tape counter drive belt (otherwise it will foul the lifting up of the Pause actuating mechanism). For EM 84 machines (not TK18) unplug & remove the EM 84 valve.

3. Remove the 3 countersunk screws that secure the Sound Channel plate (the plate that the heads are mounted to) - Note that the right hand screw also secures the top deck fixing bracket, which is normally a separate piece (if separate note its orientation for refitting). Note - in the photo (a TK 23) the deck fixing bracket is integral to the Sound Channel plate, first one I have seen like that.

For EOT (End Of Tape) sensor machines (probably not TK18) either unsolder (much easier) the EOT wire from the left hand brass sensor post or remove the wire (and sensor post) without unsoldering by undoing the tiny nut on the underside of the brass sensor post, retaining the tiny insulated washers and insulated sleeve for the post mounting hole.

4. Remove the brass cup washer from the capstan shaft. Disconnect (pull out) the Pause lever from the Pause key. Pull out the Pinch Roller actuator lever from bracket it slides in until the Pinch Roller assembly is positioned on the bottom side of the lever.

5. Carefully lift up the Sound Channel plate assembly up until it clears the top of the capstan shaft, it will be necessary to lift/ease the Pause actuating mechanism up past the tape counter pulley. Photo attachment # 1.

6. Lift/hinge the assembly over to the right side to access the top of the flywheel, being careful not to strain the head wiring cables. Photo attachment # 2.

7. Fit the new belt to the flywheel and to the motor pulley, first making sure both are clean of grease/dirt. If the capstan shaft is dirty from tape oxide deposits or rusty now is a good time to give it a good clean up.

8. Re-assemble in reverse order.
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Last edited by DMcMahon; 28th Jun 2020 at 8:55 pm.
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Old 28th Jun 2020, 9:05 pm   #9
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Default Re: Grundig TK18 Reel to Reel

Note - In photo 1 in above post the plate needs to be lifted up another 10mm approx until it gets to the top of the capstan shaft.

From the first photo in Post # 1, I guess it may also be necessary to disconnect the 2 yellow wires before attempting to lift the plate.
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Old 28th Jun 2020, 10:20 pm   #10
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Default Re: Grundig TK18 Reel to Reel

David,

Thanks for all of the above. It is most helpful of you.
I have ordered a set of 3 belts on Ebay but it will be about a week for delivery. I will post when I have done the fix.

Kind Regards,
Phil
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Old 25th Jul 2020, 3:52 pm   #11
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Default Re: Grundig TK18 Reel to Reel

Well, I followed the instructions and all the buttons worked, albeit they need to be "persuaded" using more than normal force, except for the START button which is really misnamed as it should I would have thought be labelled PLAY.

So unfortunately I am unable to see if the tape recorder plays. The problem is that this button will not push down at all, even with excessive force and so maybe I will unscrew and lift the sound channel plate out and put it back in again.

Thanks to all for your interest and advice.
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Old 26th Jul 2020, 12:37 am   #12
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Default Re: Grundig TK18 Reel to Reel

I think I know what your problem most likely is Phil but not easy to explain.

The Start (Play) button/key can get jammed solid if a small lever that is part of the mechanism gets disturbed during the lifting of the flywheel/movement of the pinch roller assembly and does not/is not re-engaged in correct place during re-assembly.

Photo 1 shows a larger horizontal lever (the left end of which engages with and actuates the pinch roller assembly) that the top end of the smaller lever engages into. A small section of the lever in question can be seen left of centre in the photo.

Photo 2 shows where I have fitted a static cleaning brush above the right hand Take Up reel table/spool which removes (lifts off) both brakes from the 2 spools, and associated linkage moves a plate on the Play mechanism which visually exposes a little more of the lever in question.

Photo 3 is a close up where you can see the small section of the lever (horizontal in this photo) in the centre of the photo.

Photo 4 is where I have additionally pushed the pinch roller assembly lever fully forwards, to move the lever in question out, so that on its left hand side you can see that its width/height is reduced, i.e. there is a a step down on both sides.

Using a long nosed pair of pliers you have to keep moving the lever until it engages fully at its bottom stepped end (left side in photo 4). It is very tricky when you are not used to doing it, but quite simple once done a couple of times.

With brush fitted (mainly to be able to see the small area better) and lever in correct place, you then will be able to move the pinch roller assembly fully back and forth and see the lever moving a lot.

Note - With brush fitted the Start Key will not press down.

David
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Old 26th Jul 2020, 2:28 pm   #13
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Default Re: Grundig TK18 Reel to Reel

I moved the Sound Channel Plate over somewhat to the left and uncoupled the Pinch Roller in an attempt to get a clearer view of the offending lever but still difficult to capture it properly.

Max upper is with the pinch roller lever assembly manually pressed fully upwards (towards the spools) , you can see the bottom (reduced width) section of the lever.

Max lower is with the pinch roller lever assembly fully down (away from the spools).

There is probably around 20m of movement between the 2 positions above.

For both I used my hand (not brush this time) to lift off the spool brakes to move the associated Play lever upwards (towards the spools direction) to more clearly see the bottom section of the offending lever.

David
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Old 26th Jul 2020, 8:52 pm   #14
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Default Re: Grundig TK18 Reel to Reel

More photos to try and explain better:-

Photo 1 - Shows the removed levers, the large lever is the lever that at its left side couples with the pinch roller lever and on its right side the lever engages with the Red or White Record button. The lever in question is the small lever with red tape leader on it, the bottom of this lever is what you have to get inserted correctly/fully.

Photo 2 - Is the same as Photo 1 but at a slightly different angle (not well focused).

Photo 3 - Is the area with the levers removed.

Photo 4 - The green tape leader shows where the bottom of the small lever has to be inserted into fully, it is quite a large rectangular opening but can be tricky to get the lever in there fully.

Photo 5 - Shows the levers back in place.

I am not suggesting that you need to remove the levers, you should not need to. It should be possible using long nosed pliers to move the bottom of the lever so that it goes into the rectangular opening fully.

If the lever is stuck outside the opening and cannot be persuaded to go into the opening then you may have to remove the levers (first take photos so that you know exactly what goes where) and refit the levers starting with angling the levers to get the small lever starting to go into the opening, it can be difficult.

To remove the levers you have to undo a single nut on the underside of the unit (first have to remove PCB metal screening cover (4 fixings) & hinge down PCB assembly to get to nut) that secures to the bottom of the shaft that the large lever rotates on (shaft and nut visible in photo 2). Note there is a spacer and flat washer at the bottom of the shaft (topside of the unity), note their positions, if they are refitted incorrectly or the nut is secured too tightly the large lever may stop rotating around its mounting shaft.

Hopefully you have already fixed it.

David
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Last edited by DMcMahon; 26th Jul 2020 at 9:06 pm. Reason: Typo correction
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Old 26th Jul 2020, 11:08 pm   #15
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Default Re: Grundig TK18 Reel to Reel

Quote:
Originally Posted by wirralman View Post
Well, I followed the instructions and all the buttons worked, albeit they need to be "persuaded" using more than normal force.
Typically all 6 operating keys/buttons are quite strong to press on this TK series. TEMP STOP (Pause) & Micro, I would say are typically the slightly weaker two.

David
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Old 27th Jul 2020, 4:38 pm   #16
wirralman
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Default Re: Grundig TK18 Reel to Reel

David,
Thanks for the time you have spent in finding a solution to my problem.
I have not managed to get the start button to operate the lever forward and engage the playing mechanism.
Eventually, I put a tape on that I know is OK on another tape recorder and played it on the Grundig by pushing the lever forward with a pencil and simultaneously pushing the fast forward button to loosen the RH spool so that the tape played.
I would have expected there to have been some sound but alas it was dead, leading me think that valves/electronics were damaged at the same time as the mechanics.
Just one point - the two leads in the photo were left disconnected. I don't know what these were for but I doubt they would be speaker leads.
Kind Regards,
Phil
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Old 27th Jul 2020, 7:26 pm   #17
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Default Re: Grundig TK18 Reel to Reel

Hello Phil,

That is a great shame but do not give up, you are maybe close.

Not sure which part you pushed with a pencil but I wonder at that time if the Record/Playback switch was not correctly in the Playback position then you might not get any sound.

Is the loudspeaker switch on rear panel switched on (position 1) ?

I think most likely the 2 yellow leads are indirectly referenced in Posts 3, 5 & 7. Can you confirm your TK 18 says Automatic on the top panel ? Unlikely to be speaker leads.

Update
- Even though an automatic machine it is possible that the "Automatic" designation may only appear on the TK 18L variant.

David

Last edited by DMcMahon; 27th Jul 2020 at 7:43 pm. Reason: Update
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Old 27th Jul 2020, 10:24 pm   #18
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Default Re: Grundig TK18 Reel to Reel

From more TK 18 research it seems like the standard TK 18 (non TK 18L) may not have the on/off loudspeaker switch on the rear panel (like most of its similar TK siblings do).

I think the 2 yellow wires should connect to a pilot lamp (effectively indicating that the unit is powered on) which would illuminate the slot in the top panel (where normally with Magic Eye models the EM84 display can be seen). Additionally as per Post 5 the pilot lamp would illuminate the "Automatic" emblem on the TK 18L de Luxe version & some versions of the standard TK 18.

Why your wires are not connected to the pilot lamp is a mystery.

Update - Maybe the lamp has been broken away, are there any signs of broken leads at the terminal strip with the 2 yellow wires ?


David

Last edited by DMcMahon; 27th Jul 2020 at 10:32 pm. Reason: Update
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