Use a connector and PCB shielding that shields the wire all the way to
the driver.

Shield all the other components inside the box in smaller, separate
boxes - for instance if you've opened a TV tuner module you'll find
that it is split into several smaller sections.  Quick google search
has these as examples:

http://www.focushacks.com/photo/dd-tvrepair/tunercover.jpg
http://www.mwrf.com/Files/30/5430/Figure_01.gif

The phone I recently disassembled* has 6 shields:
http://flickr.com/photos/adavis/2568374715/ (3 under the sticker)
http://flickr.com/photos/adavis/2569188544/

This is where adhesive copper tape is often used for prototyping.
I've also seen people use unetched PCB to form boxes soldered at the
edges.

-Adam

* (you can see the whole dissassembly here:
http://flickr.com/photos/adavis/tags/i425/ - the antenna is
particularly interesting to me - it handles all the radio traffic:
GSM/iDEN/GPS - http://flickr.com/photos/adavis/2568360833/)

On 6/18/08, Sean Breheny <shb7@cornell.edu> wrote:
> Hi all,
>
> I'm working on a DDS (Direct Digital Synthesizer) and although it
> works great, I'm having trouble keeping leakage from the several
> digital clocks in the circuit from getting into the output. I've done
> some tests which seem to indicate that even a 1cm piece of wire inside
> the (shielded) container will pick up enough leakage to be a problem
> (this is going to be the LO for a receiver). In other words, the
> problem doesn't seem to be conducted leakage through the circuit but
> rather simple coupling to the tiny bit of wire at the end of the
> shielded output cable as it connects to the PCB). So, can anyone tell
> me what the usual practice is when you have a shielded can with
> several RF signals present inside and you want to get *one* of them
> out without the others leaking in?
>
> Thanks,
>
> Sean
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>


-- 
EARTH DAY 2008
Tuesday April 22
Save Money * Save Oil * Save Lives * Save the Planet
http://www.driveslowly.org
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist