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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 31st Aug 2022, 9:40 pm   #41
Station X
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Default Re: Grundig tk 23 L speed issue

I think the actual tape speed needs to be measured for both machines.
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Old 31st Aug 2022, 10:34 pm   #42
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Default Re: Grundig tk 23 L speed issue

I think the Akai is pretty reliable. I can listen to the tape at the same time it is recorded. tape/source function I'll get back to him tomorrow. I thank you all for the help
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Old 31st Aug 2022, 11:53 pm   #43
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Default Re: Grundig tk 23 L speed issue

There is a YouTube video of an American import of the TK23L. I'll have a look to see if the capstan drive is changed.

Thank you Station X for doing the maths.

I wonder why Grundig expect the user to introduce a voltage change to the motor to compensate for the change in frequency a well as a mains input voltage adjustment for the rest of the machine. Hmm.


Chris
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Old 1st Sep 2022, 6:30 am   #44
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by ubaldojhp View Post
I think the Akai is pretty reliable. I can listen to the tape at the same time it is recorded. tape/source function I'll get back to him tomorrow. I thank you all for the help
That will give you no idea if the actual speed is correct.
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Old 1st Sep 2022, 6:41 am   #45
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Default Re: Grundig tk 23 L speed issue

I have found this diagram in the scheme.
I also found this connection tab next to the voltage one but I don't know how the wiring would go
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Old 1st Sep 2022, 9:41 am   #46
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Default Re: Grundig tk 23 L speed issue

I have just read the thread through. It seems very possible that the Akai is set for 60Hz operation and is running slow, thus making the Grundig seem fast when playing an Akai tape.
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Old 1st Sep 2022, 9:48 am   #47
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Default Re: Grundig tk 23 L speed issue

I'd agree with that. The actual tape speed needs to be measured on both machines.
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Old 1st Sep 2022, 10:11 am   #48
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Default Re: Grundig tk 23 L speed issue

I will check the Akai later. Thanks!!
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Old 1st Sep 2022, 10:56 am   #49
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Default Re: Grundig tk 23 L speed issue

Hi Ubaldo

I'm confused. At the start of this post you said the Grundig was playing the tape too fast, then you timed the playback of the Grundig v the Akai and said that the Grundig was too slow.

Am I right in thinking the suggestion is that the Grundig is OK and now the Akai needs to be altered? Help!

Ubaldo Please confirm which design of Akai 4000ds you have and the speeds you quoted for the Grundig and Akai?

NOTE: For those making suggestions to someone who is not technically experienced, the Akai 4000ds sold in EU Countries was for 50Hz only. US/Canada 110v 60 Hz and world wide only models had 110/220/240 50/60 Hz adjustment. The EU User Guide only covers EU the model.

Ubaldoon your question of where the wires go on the Grundig when looking at the photo you took David answered that for you.

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Old 1st Sep 2022, 12:06 pm   #50
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Default Re: Grundig tk 23 L speed issue

Yes Post 20, the underside of the bottom panel also the mains voltage linking information.

David
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Old 1st Sep 2022, 12:10 pm   #51
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Default Re: Grundig tk 23 L speed issue

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Originally Posted by simpsons View Post
Hi Ubaldo

I'm confused. At the start of this post you said the Grundig was playing the tape too fast, then you timed the playback of the Grundig v the Akai and said that the Grundig was too slow.

Am I right in thinking the suggestion is that the Grundig is OK and now the Akai needs to be altered? Help!


Chris
The Grundig spins faster than the Akai so the song will last less on the Grundig
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Old 1st Sep 2022, 12:13 pm   #52
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Default Re: Grundig tk 23 L speed issue

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Originally Posted by DMcMahon View Post
Yes Post 20, the underside of the bottom panel also the mains voltage linking information.

David
So the wiring would be correct.
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Old 1st Sep 2022, 12:19 pm   #53
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Default Re: Grundig tk 23 L speed issue

Nothing associated with the wiring will alter the speed of the motor by any appreciable amount. Only a change in pulley diameter will do this.

This applies to both the the Grundig and Akai machines.
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Old 1st Sep 2022, 12:36 pm   #54
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Default Re: Grundig tk 23 L speed issue

The Akai has a 50Hz/60Hz change over control on the from panel, for 50 Hz operation it should be out, if it is in the machine will run slow, I wonder if that is what is going on here?
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Old 1st Sep 2022, 3:18 pm   #55
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Default Re: Grundig tk 23 L speed issue

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Originally Posted by DMcMahon View Post
Yes Post 20, the underside of the bottom panel also shows the mains voltage linking information.

David
Missing word added above in bold.

David
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Old 1st Sep 2022, 3:24 pm   #56
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Default Re: Grundig tk 23 L speed issue

Help!!

Surely the capstan is driven by the motor by a belt and so the idler wheel will need to be changed for 60Hz? Not sure about that.

This is a domestic machine and although I might be happy taking it apart, Joe Public wouldn't so I'm not sure that this is right. There is no mention of this in the User Guide.

In addition, the TK14 User Guide, a similar chassis, specifically mentions that the motor and mains transformer need to be changed for 60Hz not the idler.

Idler drive is bad enough for a record player's wow and flutter figures, can't imagine what a 9.53 cm/s transport mechanism, even with a heavy flywheel, would sound like. Correct me if I'm wrong.

So, Ubaldo, apologies for being half asleep on the faster playback time for the Grundig you correctly wrote.

Analogueman, I can't find the 50/60Hz switch on the Akai front panel. Can you confirm which model this refers to?

Me thinks it's time to pause and take stock of where we are and what do next.

Cartagena is a large town so I wonder if there is a repair shop there who would lend a tape if only we can confirm that there is nothing wrong with the Akai?

Chris
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Old 1st Sep 2022, 3:26 pm   #57
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by Analogue man View Post
The Akai has a 50Hz/60Hz change over control on the from panel, for 50 Hz operation it should be out, if it is in the machine will run slow, I wonder if that is what is going on here?
I think only the international version has that control, most versions sold either in the US or Europe were fixed at either 60Hz or 50Hz. I assume the control, if fitted shifts the idler / belt to the appropriate part of the motor pulley.

Possibly the Akai is a US model imported later into Europe?
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Old 1st Sep 2022, 3:52 pm   #58
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Default Re: Grundig tk 23 L speed issue

I would just like to point out that an idler wheel will have no effect on tape speed. That depends on the motor speed, the ratio of any gears or belt pulleys in the drive system and the diameter of the capstan.

It's time for the OP to measure how much tape passes the head in say 30 seconds.
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Old 1st Sep 2022, 4:18 pm   #59
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Default Re: Grundig tk 23 L speed issue

Quote:
Originally Posted by simpsons View Post
Idler drive is bad enough for a record player's wow and flutter figures, can't imagine what a 9.53 cm/s transport mechanism, even with a heavy flywheel, would sound like. Correct me if I'm wrong.
I've serviced a lot of reel to reel tape recorders that have idler drive from the motor to the capstan flywheel, eg: Sony TC-366, TC-377, TC-630 etc. They sounded ok to me....and their customers.

Lawrence.
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Old 1st Sep 2022, 4:32 pm   #60
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Default Re: Grundig tk 23 L speed issue

Akai 4000DS. 220v 50Hz
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