Seeking Schematic for Commodore 840 or similar (JAPAN)

ID: 340010
? Seeking Schematic for Commodore 840 or similar (JAPAN) 
29.Jan.14 03:31

Michael Walker (CDN)
Count of Thanks: 7

Hi All,

I've recently acquired a Commodore Model 840 STEREO-MATIC-SOUND (monaural, actually) FM-AM 4 SPEAKER "8TUBE PLUS 3DIODE"  radio set. It's gonna need an alignment - the one station I like to listen to is "shadowed" by two quite loud signals either side :-(

Also, the pots are shot, very static-y and the signal cuts in and out as you move them.

I haven't done a radio alignment in almost 40 years, so hardly remember where to begin. But I am sure a schematic would be a great place to start.

Anyone seen one? I understand there were a number of very similar radios made by the same company for a couple of decades. (And this is one of the last - if not the very last - example of this set before they changed to transistors).

Tubes are 


12BA6 (x2)


12AV6 (x2)


17EW8 (??)


Any help would be greatly appreciated :-)

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Please create first the model 
02.Feb.14 15:53
87 from 3498

Ernst Erb (CH)
Articles: 5740
Count of Thanks: 8
Ernst Erb

Dear Michael

I see you are brand new to and have written this on your first day.

How nice that you start so early to be active! You might also read in the FAQ link to be able to load up some pictures of sets in your collection?

Our forum is quite different to others.
Questions about a certain model we like to have sticky for all interested later on.

This you achieve either by going to an existing model and posting from there - or - as in this case by first using the link "Create New Model" on the HP, left column above "L I N K S".

Two model admins will have to give the OK and then you can post. In this case please just tell me that it is done and I will move your question to the model and renew it, so that it comes up again. :-)


To thank the Author because you find the post helpful or well done.