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grundig: 495W ; (Spitzen-Super UKW)

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Forum » Radios and other type of sets (Physics) etc. » MODELS DISPLAYED » grundig: 495W ; (Spitzen-Super UKW)
           
Alexander Gerli
Alexander Gerli
 
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09.Jun.11 03:54

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Hello, Friends! I am having a servicve problem with my 495W -  Tubes test OK. Radio tunes, EM71 bright and indicates when stations are tuned in. However, NO audio from the speaker. The radio was working fine when put away six months ago in clean storage (our house).

I decided to use a VTVM to check the ac voltage output at the audio output transformer. Sure enough, with the volume up full, there is a small variable voltage indicating that there is some output. I clip-leaded a spare PM speaker from another similar-age radio to the transformer terminals, and there was nothing.

Can someone give me an idea just how much ac voltage I might expect at the audio out transformer?

I know the EL12 is good; just swapped it out of another working set.

I am puzzled about this. Hope someone can help me out.

Sandy AC1Y

Mark Hippenstiel
Mark Hippenstiel
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12.Jun.11 12:36

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Alexander Gerli wrote:


Hello, Friends!

I must apologise for my first post. After further investigation, I found that the EL12 end-roehre was not fully seated in its socket. I had removed it several times to substitute another EL12 and also to check the EL12 on my Taylor 45C tester. The tube tested fine. I removed the tube once again so that I could check the wiring around the output transformer. All appeared fine once again. When I replaced the tube this last time, I made sure it was pushed down well, and it seemed much tighter than before. That's when I realised what had probably happened.

I clip-leaded a spare speaker to the trafo terminals and turned the radio on once again. Sure enough, it came to life just perfectly!

In ten years of working on these great old radios I've never had this happen before. I certainly am going to make SURE about seating T-funk-based tubes from here on!

Sandy Gerli, AC1Y


 

  
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