grundig: 4055/56;

I am repairing a Grundig 4055W/3D-56 and the MW/LW/SW is working fine, but only the FM is not working. I have replaced the 10 uF elco in the FM detector, but I hear nothing than a little bit noise (with the volume at maximum level). I exchanged the EABC80 and ECC85 and doesn't matter.

When I use a small transistor FM radio to test the local oscillator of the Grundig radio and I tune this at 100.7MHz and I tune the Grundig 4055 to 90 MHz I don't hear nothing on the transistorradio. Even when I turn the dialknob from the beginning to the end of the Grundig, I don' t hear a  signal on my transistorradio.

The voltage on pin1 (anode of first triode) is 145 V, the voltage on pin 6 (anode of second triode) is about 132 V.

Does somebody know if there is a technical explanation of the FM tuner of this radio? What could be the reason that the oscillator is not working.

I use the output of the FM tuner of my Telefunken Opus 7 radio and connect it to the first grid of the Ech81 tube of the 4055 radio. Now I have a good sound, so the mf amplifiers and FM detector works fine and the problem is in the FM tuner of the 4055.

 

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Did you replace ALL the paper capacitors?  Did you replace the, "black" capacitor, in the FM "box"?!

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