RE: [softrock40] Re: Interference from PC?
MessageI don't know too much about all this, but I personally have experienced noise generated from some of the clones I have built in the past. Some of the cheaper Motherboards seem to have this problem. I am running an ASUS MB at this time and have not noticed any noise problems problems, so far. I hope I have similar results to yours, Jim.
K2 S/N 4216
-----Original Message-----I have my softrock 40 running. It's plugged into an external USB hub for
From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Jim Sheldon
Sent: Sunday, September 18, 2005 11:47 AM
Subject: RE: [softrock40] Re: Interference from PC?
power, and hooked up to my B & W broadband folded dipole. I can find no
birdies within it's limited tuning range - 7.030 to 7.080 as specified in
the AMQRP info. It is extremely sensitive, and copies signals within that
range as well as my K2 does, and that's saying something. The K2 has by far
the best receiver of any rig I've ever owned.
All this talk about computer birdies and pc noise is pretty much unfounded.
There is NO noise apparent with the scope on the DC voltage line coming from
the USB port.
The computer is a Dell Dimension 8100, Pentium IV @ 1.4GHz and even with the
covers off, I still cannot find any birds attributable to the computer.
I AM using just the bare-bones, unsupported SoundBlaster PCI sound card
that's built into the Dell's motherboard. It performs adequately for the
Soft Rock 40, but I would presume to say that if one had an SDR-1000, this
card would definitely be struggling. My sampling rate is only 48 KHz, and
it still does very well.
Maybe this will allay some of the fears I see expressed here on the
What the heck do you expect for $23 bucks a full blown SDR-1000? Jeez,
lighten up and experiment with the thing! It works as advertised, and maybe
even better considering the low end sound card I'm using.
Jim - W0EB
When I operate on the low bands (40M thru 160M) I have to turn off my
PC's. In fact I sometimes have had to unplug them completely, as the
power supply isn't completely off when the On/Off switch is in the Off
I found the problem to be caused by the computer's switching power
supply. In fact I lost a power supply in one of my computers recenly,
and replaced it with a better grade supply, and then was happy to find
that the noise from that computer was gone.
Try unplugging your computer completely and see if that quiets things
--- In firstname.lastname@example.org, "observer35" <rein0zn@i...> wrote:
> Hi all,
> Just new to the group.
> Does anybody experience interference from the PC on 40 meters?
> What about noise and garbage on the 5 V USB line?
> 73 Rein W6/PA0ZN