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

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

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

In article ,
"Matthew&Wendy" wrote:

Should I put the chokes on the cables inside, or just outside the
casing?


"Telamon" wrote in
message

.com...
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.

The chokes can be inside or outside the case. When placed inside or
outside the case the chokes should be near the case.

The metal of the case will stop a lot of the noise from getting out of
the the box. Most computer devices cases are either metal or plastic. If
plastic they will be impregnated with absorption material or there could
be conducting foil on the inside.

With the case preventing most of the circuits inside from radiating the
noise it can still get out through the cables going in and out of the
box. That is where the chokes on the cables will help.

When it comes to the monitors (CRT or LCD) noise can also radiate from
the viewing area. There are screens you can buy that are designed to be
both anti-glare and anti-RFI (Radio Frequency Interference) for the CRT
monitors. You just slip the screen over the front of the monitor and
attach a wire to a ground point on the chassis.

--
Telamon
Ventura, California

When that married Irish woman and her hubby were doing Disneyworld about
four years ago,one of the gifts I snail mailed to her via UPS at their
hotel room in Orlando was such a computer monitor screen that fits on
her 17 inch screen Gateway computer monitor.There is a little wire with
an alligator clip on the screen that is used for grounding to her
Gateway computer.Her eyes aren't too good,she said that screen I bought
at a Wal Mart store is the best thing,it really cuts down on the glare
from her computer monitor.
cuhulin