[hpsdr] Munin heat sink and spreader

[Chris Wilson]

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> Has anyone else noticed a concave surface in the heat sink in 
> the latest Munin kit?

> When I hold the copper spreader against the heat sink, it 
> touches on the ends, but the middle portion is about 1 mm away. 
>   I could:


> 1. File the copper spreader and/or aluminum heat sink to get a 
> closer fit.

> 2. Put the copper spreader in my arbor press and bend it to 
> conform to the heat sink.  But then it wouldn't be flat for the 
> transistors.

> 3. Fill the gap with something to provide a better heat transfer 
> than air.

> 4. Not worry and just screw it together.


> What do you think?


> Also, what about using Penetrox (zinc particles in petroleum) in 
> place of ordinary heat sink compound (ceramic particles in 
> silicon, I think) for the spreader/sink interface?  I've used 
> Penetrox frequently in industrial electrical work when joining 
> aluminum with copper.


> Mike - AA8K


10/10/2013 07:43

Find  a  local  engine  re-conditioner  or  machine shop and have both
mating surfaces fly cut flat. Cheap, correct and you'll sleep well :)

-- 
       Best Regards,
                   Chris Wilson.


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