telefunken: 9; Concertino

ID: 302445
? telefunken: 9; Concertino 
09.Nov.12 18:23
30

Lars-G. Lundelin (FIN)
Articles: 143
Count of Thanks: 6

In my recently acquired Telefunken Concertino 9, I had a problem with the volume pot. It was completely stuck. Couldn't get it turned neither way even with a bigsize pliers. So I had to dismantle it from the chassis and put it into the vice and tried again with the pliers. No - it was jammed.
Then I heated the spindle with a tiny pencil torch and slowly pressed the shaft out from the housing. Some kind of rough glue residues could be seen on the shaft, cleaned it up with gasolin and grinded it with fine sandpaper and lubricated. Reassembled and now it's working fine.
Are there anyone out there who have had this particular problem with a volume potentiometer?
I was lucky enough to get this pot working, these are not made for refurbishing.
Is it still possible to get this special Telefunken potentiometer on the market?

Regards
Lars-G.

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 2
Quite common problem 
09.Nov.12 21:55
30 from 2074

Emilio Ciardiello (I)
Editor
Articles: 533
Count of Thanks: 4
Emilio Ciardiello

Dear Lars,

the problem is quite common to shafts of potentiometers, tuning capacitors and little motors in turntables. It is caused by dried grease, that becomes hard just like tar. No need to dismantle the part. Usually it becomes soft enough simply heating the bushing with a soldering iron. When melted, it is possible to rotate the shaft back and forth while adding few drops of turpentine with a syringe. Usually the combined action of the manual rotation and of the solvent remove the old grease.

See also here and here

Emilio

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 3
Jammed pots 
10.Nov.12 13:06
62 from 2074

Lars-G. Lundelin (FIN)
Articles: 143
Count of Thanks: 6

 

Grazie Emilio for your prompt reply!

 

Surely it is as you say, but in my case here, it wasn't possible to remedy the problem with the pot in place.
I've been confronted with stiffy pots before and these I fixed according to your advice.
When this Telefunken pot in the vice and heated it up, I was able to turn the shaft quite easely, but when the shaft cooled down, it was jammed again.
Well, this was a new experience to the collection again. Curiously, in this set, the tuning capacitor also was jammed, but with CRC special penetrating oil into the bearings fixed easely the problem.

Regards
Lars-G.

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