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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 27th May 2020, 2:53 pm   #41
Panrock
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Default Re: Grundig TK245 overhaul

Put it all back, with a neoprene sleeve pushed up over the bottom shaft to locate the meter driving pulley instead of the damaged circlip. This seems secure and is more easily removable.

However the take up spool now doesn't turn at all, except when fast forwarding.
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Old 27th May 2020, 3:28 pm   #42
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Default Re: Grundig TK245 overhaul

Oh dear! Well, let's start with the obvious - is the belt on correctly? as you'll see, the FF is idler driven from the main pulley, and this is a belt driven slipping clutch. Not much else to it. However, do check the pulley for the counter belt isn't too tight. There isn't much torque available so the reel needs to be free to spin. Also check the brake isn't on. You'll soon have this spinning again.
That machine really does look in nice condition. As Peter says, reversing the pads should do the trick. As an aside, I think I have a spare degausser in the workshop. If you want to borrow it just ask, though it'll be around 3 to post.
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Old 27th May 2020, 3:37 pm   #43
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Default Re: Grundig TK245 overhaul

Glyn, this is really kind of you. I'll hold fire on taking you up though until I've tried the 'switch-off bias' trick. It's worth noting the playback seems fine, free of the slightest flutter, and with a CD-like velvety background silence. It's everything I had hoped from a Grundig.

I seemed to have pushed the counter drive pulley too firmly down its shaft. Pulling it back slightly made the take-up action come to life. Next to check if it's firmer and more reliable than before...
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Old 27th May 2020, 3:42 pm   #44
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Default Re: Grundig TK245 overhaul

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Originally Posted by Welsh Anorak View Post
I rather like the look of that machine - like an upmarket version of the TK124 - 144 series. I assume it takes 7" spools? The sound will probably be quite good as I think I see a tweeter lurking in there. Was it rare in this country? I notive the controls are labelled in German.
I think this is a fairly rare R2R generally. I read somewhere that it was manufactured in the UK (Belfast) but for importing to the German market, whether there is an English version I do not know.
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Old 27th May 2020, 3:57 pm   #45
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Default Re: Grundig TK245 overhaul

Based upon my own personal R2R experience, I consider that normally one would be unlucky to damage heads/make them go open circuit by testing their continuity, particularly when using digital test meters.

Having said that, last year when working on one of my Uher Royal de Luxe diagnosing a dead left channel, found that the left channel of the head was open circuit. The right channel worked OK and the head measured good continuity but a relatively short time later the right channel died and the head was then found to be open circuit.

These were Bogen heads which have a reputation for suddenly dying, so I do not really think that me testing its continuity led to its later failure.

Personally I have not experienced (nothing obvious anyway) the sound degradation of a magnetised head after head continuity checks.
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Old 27th May 2020, 4:59 pm   #46
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Default Re: Grundig TK245 overhaul

Well, the take-up still works, sort of, but still isn't firm enough for when a full 7-inch spool is put on, or anything like it.

I've tried cleaning all surfaces that are transmitting drive, and abrading the driven edge of the large disc. I've also tried fiddling with the 'adjusting screw' setting (my name), which changes the position of a small interposed 'jockey wheel'.

It's all on the attached picture. I fear the problem is basically general wear.
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Old 27th May 2020, 5:36 pm   #47
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Default Re: Grundig TK245 overhaul

Further info: it seems to be any weight on the take-up platter that's the killer, in 'play' mode. For example, I placed a reel of solder on the platter (otherwise empty) and that stalled it.

I'm sure we'll get to the bottom of this.
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Old 27th May 2020, 7:08 pm   #48
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Default Re: Grundig TK245 overhaul

I think you'll need to ascertain whether the reel is slipping against the lower white surface, or the white pulley is itself slipping as the belt's loose. Easier said than done, though!
I would doubt that a digital meter would pass enough current to magnetise the head, but an AVO 8 probably would. Like others, I have had Bogen heads fail for no obvious reason, and I have a nice Grundig TK141 that has an O/C on one head track. Annoying as it's a good machine otherwise.
I like Grundigs of this era, but find the earlier machines unpleasant to work on.
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Old 27th May 2020, 7:32 pm   #49
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Default Re: Grundig TK245 overhaul

So is the Take up spool now free to manually rotate (should spin quite easily) with brake off ?

When the tape up spool struggles in Play does the tape still get fed through by the capstan operation ?
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Old 27th May 2020, 8:24 pm   #50
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Default Re: Grundig TK245 overhaul

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So is the Take up spool now free to manually rotate (should spin quite easily) with brake off ?
Yes.

Quote:
Originally Posted by DMcMahon View Post
When the tape up spool struggles in Play does the tape still get fed through by the capstan operation ?
Yes... and that becomes/became a big problem!

I say 'became', because I have now solved this problem... by inserting a washer between the bottom gubbins and the white disc bearing the furry ring. Was there a washer there originally that flew out when I first disassembled?

So I started listening to the tape that has come with this machine. On this, someone was tuning through the FM radio band in the year 1981. I was able to deduce the year from one of the news items. Is there a sort of 'analogue' smoothness to the sound or am I imagining it? Whatever, the quality is really excellent and it makes strangely fascinating listening. I am now a R2R tape 'convert'.

More developments soon.
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Old 27th May 2020, 10:05 pm   #51
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Default Re: Grundig TK245 overhaul

That is really good news. Does it have the flat spring arm item 2 in the Service manual that has a flat washer above it, that sits below the white piece ? I assume the ends of item 2 most sit on the 2 pads (item 1).

It may be imagination/wishful thinking but I do think R2R analogue does sound particularly good.
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Old 28th May 2020, 6:59 am   #52
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Default Re: Grundig TK245 overhaul

Unfortunately I don't have the proper service manual, only The Radio & TV Servicing Book article, so am unable to refer to it to answer your question. However I suspect the answer is yes. Thanks for your continued interest.
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Old 28th May 2020, 10:43 am   #53
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Default Re: Grundig TK245 overhaul

I've just confirmed the Recording function erases the tape as it should. As for making some actual recordings and testing the auto-recording-level and low level output, I shall now have to make up a fiddly DIN lead.
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Old 28th May 2020, 11:40 am   #54
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Default Re: Grundig TK245 overhaul

Page from the manual showing the reel tables.
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Old 28th May 2020, 12:38 pm   #55
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Default Re: Grundig TK245 overhaul

Yes, and there's the washer. Thanks. If I find the original, I'll put it back.
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Old 28th May 2020, 9:08 pm   #56
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Default Re: Grundig TK245 overhaul

If you want a Service manual it can be downloaded FOC from sites such as hifiengine.com and audioservicemanuals.com, in German though so some of it can be hard work.

I find automatic translation of German technical manuals sometimes results in some very odd/confusing information in English, some of which with detective work you can work out what it is supposed to say in English.

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Old 28th May 2020, 9:32 pm   #57
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Default Re: Grundig TK245 overhaul

That's good to know. I've already joined Hifi Engine.

Otherwise, I've now successfully recorded tone, and put the Grundig back together. I shall be ordering some suitable DIN leads.
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