Saba Freiburg WIII strange resistor

      Hello,

      I am working on a Freiburg WIII and I have bumped on this strange black resistor.


      http://www.flickr.com/photos/58780736@N08/6275839495/in/photostream/lightbox/

      I am unable to find this resistor on the schematic, can anyone identify it?

      It connects on another resistor (200K) which seems to be built on top (?) of the black resistor.

      Any ideas? What is its value and how can I replace it, and most important how will I connect the 200K resistor on the replacement?

      thanks!

      Achim,
      I still have lots of trouble with replacing this resistor.

      I replaced with 2 resistors 47 Ohm and 20 Ohm 5W (the white square ones) in series and I connected a new 200K 2W resistor in between the two.

      But when I turn the radio on these resistors develop such enormous heat! you can see the change colour in a few minutes. I actually couldn't believe my eyes when I saw the solder melt at the point of connection of the three resistors!

      What am I doing wrong?

      I have checked and replaced everything which was bad on this radio, but I am stuck with this nasty resistor!
      help!

      thanks a lot
      nik

      Hi Nik,

      it seems you still have another problem that hasn´t been fixed yet.

      I assume, you have already replaced the bridge-rectifier and connected the new one / the 4 diodes correctly.

      The complete plate-current of all the tubes in the radio runs through these 2 resistors.
      So - if this current = load of the plate-circuit is too high, the resistors get hot.

      Causes could be:
      - defective audio-output-stage-tubes (EL84) remove both of them for a test,
      - defective electrolytic capacitors anywhere in the plate-circuit,
      - shorts anywhere in the wiring
      - problems caused by carbonized segments in the pushbutton switch unit
      - a short in the outputtransformer between the primary winding and ground (I hope this is not the case).

      What´s the exact voltage at the rectifier´s output and behind the ripple filter choke?

      So you will have to check everything from scratch - somewhere there´s trouble!
      Achim

      thanks again, your'e so fast,

      I have actually changed the bridge rectifier with the 4 diodes and B+ measures actually less than marked in the schematic, around 240V, therefore i didn't add a resistor.

      Let me say first that i'm quite a beginner in electronics... :)

      i have replaced 90 percent of the electrolytics and all black SABA and paper capacitors. I have only left those which measure correctly and are too far away behind wires and other components to reach (only 2-3) These are a couple of 10uf electrolytics, the long Siemens 4uf electrolytic which i cant manage to disconnect and the 0,1uf "abgeschirmt" black Saba one.

      Now, if the problem is broken plastic segments in the pushbutton section or problem in the output transformer, that's a bit too much for my knowledge to address... :)
      regards,
      Nik