Blaupunkt typ 21053

9/20/2009 8:45:09 PMIsaac Reiff

I am attempting to repair this unit and have run into a problem with the FM band. Both AM & SW work really well, however, the FM is completely out. Tubes test OK, however, without a schematic, I have no way of taking voltage readings. Are there any common issues with the FM on this set? Your help would be appreciated.

9/21/2009 1:28:34 AMJohnnysan

:I am attempting to repair this unit and have run into a problem with the FM band. Both AM & SW work really well, however, the FM is completely out. Tubes test OK, however, without a schematic, I have no way of taking voltage readings. Are there any common issues with the FM on this set? Your help would be appreciated.
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I don't have the schematic but the first thing I would check is the IF transformers.
Johnnysan-

9/22/2009 9:03:12 PMEdd

Sir Isaac. . . . .

Any chance that BLAUPUNKT receiver is using a Full Wave Bridge for the power supply rectifier ?

Plus this tube lineup:

EM87 Tuning eye

EL84 AF output

EABC80 Detector and 1st audio

EF89 IF amp

ECH81 Mixer-osc AM

ECC85 RF-Mixer FM

And is a 4 band receiver

And is about 1961 vintage

Is it in a Wood or plastic cabinet ?

73's de Edd

9/24/2009 5:05:10 PMIsaac Reiff(79463:79377)

:Edd:
Thanks for responding.
The tube lineup is spot-on except for the Tuning Eye, this radio does not have one. The cabinet is (I believe) Bakelite. Is it possible the rectifier brige is not operating as a full wave? What should my voltages be on the FM Oscillator & RF tubes?
Regards,
Isaac

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:Sir Isaac. . . . .
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:Any chance that BLAUPUNKT receiver is using a Full Wave Bridge for the power supply rectifier ?
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:Plus this tube lineup:
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:EM87 Tuning eye
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:EL84 AF output
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:EABC80 Detector and 1st audio
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:EF89 IF amp
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:ECH81 Mixer-osc AM
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:ECC85 RF-Mixer FM
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:And is a 4 band receiver
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:And is about 1961 vintage
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:Is it in a Wood or plastic cabinet ?
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:73's de Edd
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9/29/2009 12:16:44 AMEdd(79803:79463)

SIR Isaac. . . . .

Ach himmel. . .I’m dun bin tellink you VOT . . .ve are bin havink undt big problink in locatink schmitt der schematic info fer der Svedish BLAUPUNKT 21050 .

I am thinkink I’m in findink it !
Check to see that the FM tuner is getting mechanically rotated my the frontal FM tuning knob.

If no FM reception, start by pulling the Ecc85 tube and scraping all of its pins . . .lengthwise . . .all around each pin . .clean and shiny as can be . . .right up to the glass bottom.

Then plug it in and out of its socket about 3 or 4 times and then fire up the set.

Go down to my YELLOW [A] mark up reference and monitor that grid looking for a negative voltage and then tune thru the FM band slowly. If the FM front end up to that point is working OK, there will be quite a noticeable increase in negative voltage as a station is tuned into, and then it will drop down as the stations is tuned off from.

If no sound, we must be losing it on past that point, on towards the detector and AF stages.

73's de Edd

UNAVAILABLE BLAUPUNKT SCHEMATIC INFO . . .as a giant unitized format: