There is no casing. You put the ferrite on each end of the audio cable.
Personally, I don't find this very effective. The ferrite is better
than nothing, but you won't eliminate all the noise.

You can do a few experiments to find the noise of the source. For
instance, start the PC recording the audio, then turn off your monitor
and see if the noise level goes down.

Unless you have a PC with power factor correction in the power supply,
your PC will really polute the mains, which in turn is either picked up
by the antenna from the power line radiation, or feeds into your radio
via the power line. If you have a notebook computer, you can try
running the notebook from the battery rather than the mains.

If you have a wellbrook, try moving the antenna further away from the
PC. In general, keep the PC as far away from the antenna as possible.

Matthew&Wendy wrote:
Should I put the chokes on the cables inside, or just outside the casing?


"Telamon" wrote in message
...
In article ,
"Matthew&Wendy" wrote:

I like to use my computer to translate CW and record shortwave. However,
the
computer throws out a lot of RFI. If I build a Faraday cage around it,
will
this help? Does the cage need to be grounded?

Matthew Plante
KC2KEI
Scars are the proof that man can survive his own stupidity.

Building a Faraday cage around the computer would be a lot of work. Most
of the noise is radiated from the cabling so use ferrite common mode
chokes on the cables.

--
Telamon
Ventura, California