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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 30th Aug 2022, 1:45 pm   #21
simpsons
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Default Re: Grundig tk 23 L speed issue

Hi David and Ubaldo

Just in case scanning the TK23L User Guide is delayed, the TK14 "Operating Instruction Manual" in English is online.

Whilst the TK14 differs in facilities, the chassis is similar together with controls and the basics of selecting the input, recording and playback which are all covered.

I hope this helps.

Chris
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Old 30th Aug 2022, 2:06 pm   #22
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by ubaldojhp View Post
Sorry if I'm doing something wrong. I'm trying to record something from Grundig itself but I don't think I'm doing it right. I connect the ipod to the input and press the red key and play but it doesn't record. Only the music already recorded on the tape is heard
So when you record, the original recording on the same section of the tape is not erased, correct ?

When you do an automatic recording with the red record button pressed straight down and aligned with the "A" do you see any record signal on the Magic Eye valve, this is the recording level. The Magic Eye has a green display with a dark/black section, the black section width will vary in line with the amplitude of the record signal.

When you do a manual recording you twist the record button 45 degrees clockwise before pushing it down, it then is aligned with the black circle symbol. You then adjust the volume control (which is the record level control during recording) to get a strong record signal which is denoted by the black section of the Magic Eye reducing down to a narrow black vertical line on the strongest parts of the music/record signal.

For non microphone recordings the Micro button must not be pressed down, for microphone recordings the Micro button must be pressed down.

Ensure you have wired the recording cable correctly. Pin 1 for the live signal and pin 2 for the screen, at the Micro, Diode & Radio DIN connectors.

David
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Old 30th Aug 2022, 2:10 pm   #23
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Default Re: Grundig tk 23 L speed issue

Thank you very much. I'll get to it this afternoon. They have all been very kind
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Old 30th Aug 2022, 8:43 pm   #24
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Default Re: Grundig tk 23 L speed issue

This afternoon I have been doing tests. Recording is not working at the moment. Pressing the red button is only heard in playback mode and the magic eye does not move either. But first I have to solve the issue of speed. I have compared the speed of the reels with the Akai 4000ds and in the grundig it spins faster in 3 3/4 mode so I think I rule out a bad recording in the akai
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Old 30th Aug 2022, 9:11 pm   #25
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Default Re: Grundig tk 23 L speed issue

User Manual scanned and 28 pages emailed.

As well as the TK 23L, the manual also covers the TK14L, TK17L & TK18L.

David
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Old 30th Aug 2022, 9:29 pm   #26
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Default Re: Grundig tk 23 L speed issue

Thanks a lot David
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Old 31st Aug 2022, 9:38 am   #27
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by ubaldojhp View Post
Pressing the red button is only heard in playback mode
Do not understand what this part means ?

David
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Old 31st Aug 2022, 10:02 am   #28
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Default Re: Grundig tk 23 L speed issue

Hi Ubaldo

I'm reading this post on your Grundig TK23L with interest and David's expert help.

Counting the rotation of the spools on each machine is not the same as measuring the tape speed viz 3/34 ips or 9.53 cm/s past the recording head.

The spools will rotate at a speed depending on how much tape is already wound on them. The more tape on the right hand spool the slower it needs to rotate because the circumference of the spool of tape is now larger and so on.

Having the user instruction manual from David will make everything clear but do make sure that you have the correct DIN lead to make recordings on the Grundig. I see that the Akai also has a DIN and phono socket. Have you been using a DIN lead to record on the Akai? The DIN lead will work on both.

Chris
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Old 31st Aug 2022, 10:10 am   #29
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Default Re: Grundig tk 23 L speed issue

No cris, in the akai I use rca. I'll have to go over the inputs in case my cable wasn't the right one or change to rca. David, I think I'm doing it right or so I think. I press the red record button at the same time as the play key. The magic eye does not move and the tape is heard but at a higher volume. Forgive my ignorance but it is the first valve reel that I restore. I have had others but have used them for spare parts or to build an amp
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Old 31st Aug 2022, 10:16 am   #30
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Default Re: Grundig tk 23 L speed issue

I have compared the speed of the reel with the akai at the beginning of the tape, both. The akai at the beginning of the tape seems to rotate more slowly than the Grundig, I always refer to the right reel
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Old 31st Aug 2022, 10:56 am   #31
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by ubaldojhp View Post
I press the red record button at the same time as the play key. The magic eye does not move and the tape is heard but at a higher volume.
So are you saying that during a recording with the red record button down you hear the tape ? is what you hear the original recording on the tape or the new music you are trying to record ?

David
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Old 31st Aug 2022, 11:18 am   #32
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Default Re: Grundig tk 23 L speed issue

The original recording
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Old 31st Aug 2022, 12:28 pm   #33
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Default Re: Grundig tk 23 L speed issue

If I understand you correctly then it sounds like the machine is not switching to Record mode when you push the red recording button down, if so then presumably you see/hear no difference between playing the tape and trying to record, i.e. you always hear what is already on the tape.

If so then one explanation could be that the Record/Playback switch is not being mechanically actuated.

With the bottom cover removed and machine unplugged from the mains voltage (and allow time for capacitors to discharge) look at the underside top right corner of the machine and you should see the Record/Playback switch actuator arm move around 5mm when the Record button is pressed down.

Photo 1 shows the switch in the Playback position. Photo 2 shows the switch in the Record position. Photo 3 shows the end of the Record/Playback actuator arm. Photo 4 shows Record button actuating mechanism.

Possible faults could be that the Paxolin part of the switch actuator arm has broken off (I had this once) or the Record button actuating mechanism is not engaging in the rectangular cut-out hole in the Paxolin arm (this can fairly easily happen if the PCB has been hinged down and the Record button actuating mechanism has not been fitted back into the switch arm when PCB is hinged back up.

David
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Last edited by DMcMahon; 31st Aug 2022 at 12:34 pm.
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Old 31st Aug 2022, 3:35 pm   #34
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Default Re: Grundig tk 23 L speed issue

Hi Ubaldo,

cc David

Ubaldo thank you for explaining how you compared the tape speed between the 2 machines.

May I suggest that you do this though by playing back say 60 seconds on the Akai, stop and, turning the tape over, play it on the Grundig and note how long it takes to reach the same point on the tape. Choose the start as the point where the clear leader joins the oxide tape. The tape moves at 9.53cm/second and a simple calculation will see if the Grundig is way out as you think.

Counting the number of rotations of the spool is OK with me but it doesn't indicate how far out the speed is. Following my suggestion, hopefully, will point to any fault. Philips have test tapes which record a tone for x seconds to do just that.

Chris
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Old 31st Aug 2022, 7:29 pm   #35
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Default Re: Grundig tk 23 L speed issue

Hi Chris, I have put the first song and in the Grundig it lasts 4:16. On the other hand, in the Akai it is 5:11 min.
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Old 31st Aug 2022, 7:31 pm   #36
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Default Re: Grundig tk 23 L speed issue

Hi David, the piece you refer to is loose. It is seen in photo 4. I will try to put it in its place
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Old 31st Aug 2022, 8:41 pm   #37
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Default Re: Grundig tk 23 L speed issue

Not sure what you mean by loose, if you mean that it is not engaged into the Play/Record switch actuator, then try and re-engage it.

If it is not engaged you may have to loosen/remove the 4 securing screws for the PCB to enable the PCB to be moved a little to be able to engage photo 4 item.

If the 4 securing screws and spacers are removed note that the ones on the left hand side are shorter. If the PCB is hinged down you will find that photo 4 item is loose/will swivel 90 degrees upwards around its mounting shaft.

Any doubt then get photo (s) showing how yours is.

David
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Old 31st Aug 2022, 8:47 pm   #38
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Default Re: Grundig tk 23 L speed issue

Hi Ubaldo,

Are your times the right way around? I thought you started this post saying the Grundig was too fast.

I know that your working on David's advice to check the record switching when you depress the red record button, but when your ready just confirm the time measurements stated.

On the face of it, there is one hell of a speed/time difference between the two.

Chris
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Old 31st Aug 2022, 9:27 pm   #39
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Default Re: Grundig tk 23 L speed issue

4 minutes 16 seconds is 256 seconds. Multiply 256 by 1.2 and you get 307.2 seconds or 5 minutes and 7 seconds. That isn't far off the 5 minutes and 11 seconds quoted.

60Hz/50Hz is 1.2. Is this a mains frequency problem?
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Old 31st Aug 2022, 9:37 pm   #40
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Default Re: Grundig tk 23 L speed issue

Coming back to the possibility (slight) that a 60Hz motor pulley might be fitted.

I measured my 50Hz pulley, a nominal 20.8mm at the top (above the drive belt groove) and a nominal 23mm at the bottom (below the drive belt groove). 50Hz pulleys are not normally marked as 50 but 60Hz pulleys maybe marked.

When you press your red record button down does it stay locked/latched down when you stop pressing it down ? Mine does and then to release it you have to press the Fast Forward key, this seems incorrect. Normally (at least on non L/Deluxe models) you have to press and hold the record button down then press the Play/Start key down in order to latch the Record button down.

David
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