I have an Eton E5 which I connect to my laptop via the Line Out on the
Eton to the Line In on the laptop.

This works great for recording shortwave broadcasts, but if the laptop
is plugged in, it generates some interference on the radio (only when
they are connected via lineout / in). If I unplug the laptop, there is
no interference.

Does anyone know if there is anything I can do to get rid of the
inteference? I want to set up my machine to record programs overnight,
so I can't leave the laptop unplugged.

mike

http://mesh.typepad.com

"Mike Chambers" wrote in message
news
I have an Eton E5 which I connect to my laptop via the Line Out on the
Eton to the Line In on the laptop.

This works great for recording shortwave broadcasts, but if the laptop
is plugged in, it generates some interference on the radio (only when
they are connected via lineout / in). If I unplug the laptop, there is
no interference.

Does anyone know if there is anything I can do to get rid of the
inteference? I want to set up my machine to record programs overnight,
so I can't leave the laptop unplugged.

mike

http://mesh.typepad.com

How about a real long line in cable? I got lots less noise when recording into my laptop
when I could get the radio farther away.

Mike Chambers wrote:

I have an Eton E5 which I connect to my laptop via the Line Out on the
Eton to the Line In on the laptop.

This works great for recording shortwave broadcasts, but if the laptop
is plugged in, it generates some interference on the radio (only when
they are connected via lineout / in). If I unplug the laptop, there is
no interference.

Does anyone know if there is anything I can do to get rid of the
inteference? I want to set up my machine to record programs overnight,
so I can't leave the laptop unplugged.

mike

http://mesh.typepad.com

You have a ground loop. Get an isolation transformer, say
Radio Shack 270-054A about $15, and insert it in the connecting audio
cable.

--
Ron Hardin


On the internet, nobody knows you're a jerk.

Thanks. That is exactly what I was looking for.

mike

On Thu, 04 Jan 2007 02:00:15 GMT, Ron Hardin
wrote:


You have a ground loop. Get an isolation transformer, say
Radio Shack 270-054A about $15, and insert it in the connecting audio
cable.

Hello, you can also get some noise-reduction ferrite core, such as this :

http://www.shinemicro.com/images/ferritethumb.jpg

Perhaps you have some already clamped on some device's wire (digital
camera, AC/DC tranformer, modem, etc...).

If you can un-clamp one a clamp it on your laptop power wire OR audio
line wire, just check if it helps...

I did that on my AC/DC adapter of my SW radio, and it helps reducing (a
little) incomming RFI.

Charly

Unfortunately that didn't solve the problem.

Any other ideas? I want to be able to automate recording some
frequencies over night, but I cant right now, as I have to keep the
laptop plugged in, which is causing significant static / interference.

mike

On Thu, 04 Jan 2007 02:00:15 GMT, Ron Hardin
wrote:


You have a ground loop. Get an isolation transformer, say
Radio Shack 270-054A about $15, and insert it in the connecting audio
cable.

Thanks. That didnt seem to help any.

mike

On Thu, 04 Jan 2007 10:47:45 +0100, Charly wrote:


Hello, you can also get some noise-reduction ferrite core, such as this :

http://www.shinemicro.com/images/ferritethumb.jpg

Perhaps you have some already clamped on some device's wire (digital
camera, AC/DC tranformer, modem, etc...).

If you can un-clamp one a clamp it on your laptop power wire OR audio
line wire, just check if it helps...

I did that on my AC/DC adapter of my SW radio, and it helps reducing (a
little) incomming RFI.

Charly

Talk to some people at a local radio station,or tv station.They might
have some good tips.I know some radio and tv stations record programs to
computer files/data.
cuhulin

Mike Chambers wrote:
Unfortunately that didn't solve the problem.

The transformer should have fixed the problem. The noise is most likely
coming from the laptop switched-mode power supply. Have you tested it
while running on batteries alone?

I have several radios connected to computers, and for this I use the
Buxcomm Rascal GLX (www.buxcomm.com) and this works for both of my pc's
and my laptop.
The Rascal is also available as a kit for transceivers and you can
build just the receive side if you wish. That said, the transformer
alone should be enough, and there is the possibility that you did not
assemble the cable shielding correctly or add sufficient bypassing.

My computers receive audio, decode it and post it to my webpage. This
system does work, do not despair.

Brad
www.vk2qq.com

Mike Chambers wrote:
...

Mike:

Here is an interesting link:

http://www.waypoint.com/users/~disco...esentation.htm

One circuit I seen on this page makes use of an opto-isolator. Seems to
me that with a led and photo-transistor one could kludge together a unit
which would seem to perform miracles!!!

Warmest regards,
JS