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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 9th Dec 2018, 4:44 am   #21
Phantomrose1999
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Default Re: Help Pls = Grundig TK64 Motor Not running

Yes, i have no explanation, as having traced the wiring, adding the 5uF to the motor tags, between A and C, should have made it work. Because these motor tags go straigh to the 4.3uF capacitor and the motor coils. Oh well..

Video of Chassis Splitting
https://www.youtube.com/watch?v=vQTPYFB_KBU

Testing after putting it back together
https://www.youtube.com/watch?v=A6ZfUJS8Fwo

Well, thats the end of the story, and i hope all this helps anyone who wants to restore a TK64, TK60, TK30..etc. They are all pretty much the same.

I bought a TK60, just down the road from me 2 days ago, in case i needed parts.

Next however will be an immaculate TK46 i bought, almost brand new, just low volume and sound quality not what it should be. One owner bought in Germany, and has every document and about 20 grundig boxed tapes, some unopened !! Museum quality, if there was such a thing..ha.
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Old 9th Dec 2018, 12:38 pm   #22
Reelman
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Default Re: Help Pls = Grundig TK64 Motor Not running

Great news!
Thanks for the write-up, you never know when you might be in the same boat!
Peter
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Old 12th Dec 2018, 2:34 pm   #23
Phantomrose1999
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Default Grundig TK64 "The story continues" Head Coil open on one Channel

Hi all the Grundig addicts

After 13 videos and lots of work over the past few months, i though i had fully restored my Grundig TK64.

https://www.youtube.com/watch?v=A6ZfUJS8Fwo

While testing i realised the switch was in MONO all this time, and while its records and plays well in MONO, when i switched it to STEREO, only the left channel was playing...oh dear !

Investigation has shown one of the two coils in the head is open circuit ! hence the problem.

See photos.

I have a TK60 for spares and possible restoration one day, and its hard to believe but the head is working, BUT its about 500 ohms per coil.
Unfortunately the whole rest of the unit needs restoration.

QUESTIONS:

Given the chances of getting a working head for this model is rather slim, has anyone tried to transplant a more modern head ?

The working coils restistance is about 1K ohms. Perhaps i can just find another one with a similiar resistance and physical fit ?

PS: A photo of my latest addition a TK46 that is like new, with every factory document, including deliver tags with the serial number. Will do a video on it, after i replace the belts and pinch roller. The rest is working well.
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Old 12th Dec 2018, 3:25 pm   #24
Phantomrose1999
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Default Re: Grundig TK64 "The story continues" Head Coil open on one Channel

As this is a Record / Play head, and the later units like the TK46 have a separate Record / play head, can someone explain whats the difference in design that allows one type to Record / Play and the others as being PLAY or RECORD only.. TKs
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Old 15th Dec 2018, 2:01 pm   #25
Phantomrose1999
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Default Re: Help Pls = Grundig TK64 Motor Not running

This afternoon i came across a Sony TC-230W, Stereo Reel to Reel, with an integrated Record/Play head. So i bough it

Opened it up and its almost immaculate inside, cant see any corrosion or rust of anything that warrants its fate.. The motor works like a dream, cant tell if its running.

The power supply has an internmittent problem, sometimes there is power somethings there is not, when i was shaking the chassis around it came to life and then went off again...oh well

I removed the play / record head, and unfortunately its on 27 ohms per coil !! as opposed to theTk64 which is 1K ohms, and the TK60 which is about 500 per coil.. So looks like transistor unit heads have a low resistance compared to valve unit... so the hunt countinues..

now what to do with the Sony TC-230W....hmmm
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Old Yesterday, 1:35 am   #26
julie_m
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Default Re: Help Pls = Grundig TK64 Motor Not running

Quote:
Originally Posted by Phantomrose1999 View Post
I removed the play / record head, and unfortunately its on 27 ohms per coil !! as opposed to theTk64 which is 1K ohms, and the TK60 which is about 500 per coil.. So looks like transistor unit heads have a low resistance compared to valve unit... so the hunt countinues..
Yes -- as a general rule, valves work with voltages, whereas transistors work with currents. To impart the same amount of energy to the tape, a head being driven at the kind of low current valves can manage will need a higher resistance to develop a larger voltage (watts = volts * amps and volts = amps * ohms) than a head being driven by a transistor circuit that can put out more current than a valve, but cannot withstand such high voltages.

Quote:
Originally Posted by Phantomrose1999 View Post
now what to do with the Sony TC-230W....hmmm
Fix its power supply, of course, and have two working stereo tape recorders! Then when you've had about as much fun as you can with a two-head recorder, you'll need to look for a three-head machine. And maybe you'll be ready to see what can be done with separate reel and capstan motors -- the Japanese (perhaps necessitated to some extent to the use of two different mains frequencies, 50 and 60Hz side-by-side) managed to squeeze a lot of functionality out of just one motor, but there is always room for improvement ..... Tape recorder collecting can be addictive!
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