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Old 10th Sep 2019, 9:24 pm   #34
DonaldStott
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Join Date: Aug 2015
Location: Glasgow, UK.
Posts: 1,203
Default Re: Kolster-Brandes MR10

Trying to unpick the connections on the underside of V2 was quite challenging but this annotated picture (labels and values correspond to the KB Museum service manual) is what I have surmised so far :-

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This is where I think the connections are: -

C45 (0.01μF) Pin 1 to Pin 7
C44 (0.01μF) Pin 1 to Pin 3
C15 (1000pF) Pin 3 to Ground

C46 (10pF) Pin 8 to Pin 3 of V3
C12 (410pF) Pin 9 to S2

R39 (22kΩ) Pin 9 to Ground
R33 (220Ω) Pin 7 to Ground

I'm struggling a bit with R31 (15kΩ) which I think is connected to Pin 3 and S1 - assuming that it is the one identified in the above picture just visible on the other side of the metal dividing plate in the FM stage?

Now on the assumption that the above is correct I need to replace the Hunts Mouldseals along with R33 and R39, both of which are at least 25% above their stated values, in circuit of course.

As it's a real guddle of connections in there what's the best practice advice on how to un-solder the old components, solder the new ones and in what order - not really enough space for the usual spirals I've used elsewhere?
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