grundig: 5040GW/3D; Konzertgerät

ID: 273202
grundig: 5040GW/3D; Konzertgerät 
16.Dec.11 16:23
2007

James Miller (USA)
Articles: 7
Count of Thanks: 5
James Miller

I am restoring a Grundig 5040W/3D and want to share photographs and what I have learned.  I have uploaded some photographs from the initial steps of restoration.  I used schematics and forum information from radiomuseum.org, thank you!

Here is what I have done so far:

Replaced almost ALL capacitors - most of the paper capacitors were bad, leaky or out of tolerance.  They have been replaced with modern capacitors, some of them were replaced with "Orange Drop" capacitors (see photos).  Special consideration given to any coupling capacitors such as the one that drives the grid of the EL-12 tube.  A shorted or leaky capacitor here will place positive voltage on the grid causing the tube to conduct heavily and over heat.  Evidence is seen in the cathode resistor of the EL-12 which may be burned or actually smoke!

Replaced selenium rectifier with modern silicon rectifiers - the original rectifier in the black can (probably selenium) had too much resistance and over heated, so the high voltages to the tubes was too low.  Replaced with four 1KV 1A silicon diodes (see photo).  The set really came alive after that!   I left the old rectifier on the chassis and simply clipped its leads to preserve as much of the original look as possible.

Replaced some weak tubes.   I used a tube tester to identify bad tubes and replaced them.  All except the EL-12 and EF804 have American equivalents. 

The full resolution (large) photos of the project are available on Photobucket at this LINK.

I will try to post more information as the project continues.

 

James Miller

 

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