Elecraft

Re: DSP and CW

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Ian Maude

Re: DSP and CW

Thanks to Tom N0SS and Lyle KK7P for pointing out the blindingly obvious
mistake on my part! I have obviously changed the settings but I can't
remember it at all! I must have done it though ;-)

I had the centre set outside the tone and so I could hear nothing.
Actually it could be seen quite easily with Spectrogram.

Now, on with that code, thanks guys.

Ian
--
Ian Maude G0VGS Morecambe Lancs UK | [hidden email]
Sysop of GB7MBC, the Morecambe Bay Cluster
Running Linux and DXSpider | K2 #4044

DX and Cluster forums at http://www.gb7mbc.net/forum/

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tom.w3qs

Interference from Computers

Good Morning Group,

I am back on the air (4991) after nearly 20 years. The first thing I
noticed was all the interference on 20 meters. Hetrodynes everywhere!
What's going on?

Took me a while to figure out that it was the computer - not there 20 years
ago!

So, other than removing it from the shack (ghastly thought) is there any
font of wisdom on this subject or general guidance?

Thanks and 73,

Tom, W3QS

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Brian Short

Re: Interference from Computers

On Aug 10, 2005, at 5:03 AM, tom.w3qs wrote:
> So, other than removing it from the shack (ghastly thought) is there
> any
> font of wisdom on this subject or general guidance?

I had this problem and the issue was the switching
power supply. I installed a different power supply
and it was fixed.

Also, the problem could be radiation from cables that
come out of the computer.

One suggestion I was given is to try disconnecting all
cables (other than power) and see if the noise is from
the case itself.

Good luck.
--
73, Brian (K7ON)
http://members.cox.net/bshort4/

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Mark J. Schreiner

Re: Interference from Computers

In reply to this post by tom.w3qs

Move the "shack" to the great outdoors to operate from a nice portable quiet location. Our local township park (only bad part of mine is the HV power distribution wires running right through it, about 300 feet from our favorite tall tree -- aka antenna support, and a picnic table) is fairly quiet. I've taken the radio out along the Appalachian Trail (thanks to the EPA QRP Club) as well, talk about quiet! All of that fun outdoor operating doesn't take away from Field Day, though, that is still fun too.

Mark, NK8Q
K2 4786

>From: "tom.w3qs" <[hidden email]>
>Date: Wed Aug 10 07:03:59 CDT 2005
>To: 'Elecraft Reflector' <[hidden email]>
>Subject: [Elecraft] Interference from Computers

>Good Morning Group,
>
>I am back on the air (4991) after nearly 20 years. The first thing I
>noticed was all the interference on 20 meters. Hetrodynes everywhere!
>What's going on?
>
>Took me a while to figure out that it was the computer - not there 20 years
>ago!
>
>So, other than removing it from the shack (ghastly thought) is there any
>font of wisdom on this subject or general guidance?
>
>Thanks and 73,
>
>Tom, W3QS
>
>
>_______________________________________________
>Elecraft mailing list
>Post to: [hidden email]
>You must be a subscriber to post to the list.
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>Elecraft web page: http://www.elecraft.com

Don Wilhelm-3

RE: Interference from Computers

In reply to this post by tom.w3qs

Tom,

The worst offender is usually the CRT type monitors - I replaced the monitor
on my own and the XYL's computers with an LCD display and most of the
interference went away.

Yes, a computer is an 'essential' element in the shack today, so it is a
device that must be dealt with for better or worse.

73,
Don W3FPR

> -----Original Message-----
>
> I am back on the air (4991) after nearly 20 years. The first thing I
> noticed was all the interference on 20 meters. Hetrodynes everywhere!
> What's going on?
>
> Took me a while to figure out that it was the computer - not
> there 20 years
> ago!
>
> So, other than removing it from the shack (ghastly thought) is there any
> font of wisdom on this subject or general guidance?
>
> Thanks and 73,
>
> Tom, W3QS
>

--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.338 / Virus Database: 267.10.5/67 - Release Date: 8/9/2005

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Bob - W5BIG

Re: Interference from Computers

In reply to this post by tom.w3qs

Hi Tom,

One major source of noise is the CRT monitor. It helps to make the screen
display as uniform as possible, like a blank window or a plain background
without texture.

73/ Bob - W5BIG

----- Original Message -----
From: "tom.w3qs" <[hidden email]>
To: "'Elecraft Reflector'" <[hidden email]>
Sent: Wednesday, August 10, 2005 7:03 AM
Subject: [Elecraft] Interference from Computers

> Good Morning Group,
>
> I am back on the air (4991) after nearly 20 years. The first thing I
> noticed was all the interference on 20 meters. Hetrodynes everywhere!
> What's going on?
>
> Took me a while to figure out that it was the computer - not there 20
years

> ago!
>
> So, other than removing it from the shack (ghastly thought) is there any
> font of wisdom on this subject or general guidance?
>
> Thanks and 73,
>
> Tom, W3QS
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

ROBERT CARROLL-4

RE: Interference from Computers-Routers

I have recently moved to a new QTH and am slowly getting things in shape to
get back on the air. I ran into a lot of nasty RFI problems. The previous
owner had installed "smart house" wall switches throughout the house. They
were supposed to control incandescent lamps only, but in fact they
controlled fans, wall outlets, etc. Besides sending a few entertainment
radios to the dump before I figured out what was going on, the RFI was
horrendous. Gradually I removed them only to find I still had problems.
While doing some electrical work an electrician found the signal injector
for the system behind the main breaker panel, and that eliminated nearly all
the noise.

I should say nearly all the broadband noise, as I was left with birdies
about every 30 kHz or so. Eventually I tracked those down to a Linksys
Wireless G router, model wrt54gs. My previous Linksys bit the dust just
before I moved, so I can't say if I would have heard the birdies from this
one had I installed it in the old QTH. I have wireless and wired
connections running off this router, and have helped the problem by
installing ferrite on the power wart lead and all the data leads. But I
have not been able to eliminate the rather broad birdies that seem to fall
at nice dx frequencies.

Has anyone on the reflector had such a problem and found a way to cure it?
Searching on the internet I find that RFI from routers is a well known
phenomenon, but I have seen no suggestions for curing the problem.

Bob W2WG

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Bob - W5BIG
Sent: Wednesday, August 10, 2005 9:32 AM
To: tom.w3qs; 'Elecraft Reflector'
Subject: Re: [Elecraft] Interference from Computers

Hi Tom,

One major source of noise is the CRT monitor. It helps to make the screen
display as uniform as possible, like a blank window or a plain background
without texture.

73/ Bob - W5BIG

----- Original Message -----
From: "tom.w3qs" <[hidden email]>
To: "'Elecraft Reflector'" <[hidden email]>
Sent: Wednesday, August 10, 2005 7:03 AM
Subject: [Elecraft] Interference from Computers

> Good Morning Group,
>
> I am back on the air (4991) after nearly 20 years. The first thing I
> noticed was all the interference on 20 meters. Hetrodynes everywhere!
> What's going on?
>
> Took me a while to figure out that it was the computer - not there 20
years

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roncasa

Re: Interference from Computers-Routers

Wow, good work Bob.
Thank you for sharing it with us. I made my wife throw out all (2) the
touch lamps and removed all "dimmer" switches. (It makes the radio
"dim") but never thought about the router causing birdies that I do have
(always on your favorite freqs).
Can you explain what the signal injector behind the panel was for?
Ron wb1hga
(still not entirely noise free, yet)

ROBERT CARROLL wrote:

> I have recently moved to a new QTH and am slowly getting things in shape to
> get back on the air. I ran into a lot of nasty RFI problems. The previous
> owner had installed "smart house" wall switches throughout the house. They
> were supposed to control incandescent lamps only, but in fact they
> controlled fans, wall outlets, etc. Besides sending a few entertainment
> radios to the dump before I figured out what was going on, the RFI was
> horrendous. Gradually I removed them only to find I still had problems.
> While doing some electrical work an electrician found the signal injector
> for the system behind the main breaker panel, and that eliminated nearly all
> the noise.
>
> I should say nearly all the broadband noise, as I was left with birdies
> about every 30 kHz or so. Eventually I tracked those down to a Linksys
> Wireless G router, model wrt54gs. My previous Linksys bit the dust just
> before I moved, so I can't say if I would have heard the birdies from this
> one had I installed it in the old QTH. I have wireless and wired
> connections running off this router, and have helped the problem by
> installing ferrite on the power wart lead and all the data leads. But I
> have not been able to eliminate the rather broad birdies that seem to fall
> at nice dx frequencies.
>
> Has anyone on the reflector had such a problem and found a way to cure it?
> Searching on the internet I find that RFI from routers is a well known
> phenomenon, but I have seen no suggestions for curing the problem.
>
>
> Bob W2WG
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bob - W5BIG
> Sent: Wednesday, August 10, 2005 9:32 AM
> To: tom.w3qs; 'Elecraft Reflector'
> Subject: Re: [Elecraft] Interference from Computers
>
> Hi Tom,
>
> One major source of noise is the CRT monitor. It helps to make the screen
> display as uniform as possible, like a blank window or a plain background
> without texture.
>
> 73/ Bob - W5BIG
>
>
> ----- Original Message -----
> From: "tom.w3qs" <[hidden email]>
> To: "'Elecraft Reflector'" <[hidden email]>
> Sent: Wednesday, August 10, 2005 7:03 AM
> Subject: [Elecraft] Interference from Computers
>
>
>
>>Good Morning Group,
>>
>>I am back on the air (4991) after nearly 20 years. The first thing I
>>noticed was all the interference on 20 meters. Hetrodynes everywhere!
>>What's going on?
>>
>>Took me a while to figure out that it was the computer - not there 20
>
> years
>
>>ago!
>>
>>So, other than removing it from the shack (ghastly thought) is there any
>>font of wisdom on this subject or general guidance?
>>
>>Thanks and 73,
>>
>>Tom, W3QS
>>
>>
>>_______________________________________________
>>Elecraft mailing list
>>Post to: [hidden email]
>>You must be a subscriber to post to the list.
>>Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>>Help: http://mailman.qth.net/subscribers.htm
>>Elecraft web page: http://www.elecraft.com
>>
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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>
>
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>

Mark J. Schreiner

Re: RE: Interference from Computers-Routers

In reply to this post by ROBERT CARROLL-4

Possibly the best clue you gave was the ferrites that you added to the wall wart for the Linksys wireless G router, and the 30 kHz spacing on the spurs. This sounds to me like the wall wart may be a switching supply. Maybe if you got a linear regulated supply for the router to replace the wall wart the spurs would go away. That is assumming they are coming from the wall wart if the switching supply is built into it, as compared to if the switching part is in the router itself.

Thanks for the "heads up" on the Linksys router. I was about to get a wireless network going myself to get a link out to the garage for a remote radio beacon (PropNetPSK31 on 10m) project I'm working on. Maybe I'll start with a D-link wireless G router instead.

73,

Mark, NK8Q
K2 4786

>From: ROBERT CARROLL <[hidden email]>
>Date: Wed Aug 10 09:17:15 CDT 2005
>To: 'Elecraft Reflector' <[hidden email]>
>Subject: RE: [Elecraft] Interference from Computers-Routers

>I have recently moved to a new QTH and am slowly getting things in shape to
>get back on the air. I ran into a lot of nasty RFI problems. The previous
>owner had installed "smart house" wall switches throughout the house. They
>were supposed to control incandescent lamps only, but in fact they
>controlled fans, wall outlets, etc. Besides sending a few entertainment
>radios to the dump before I figured out what was going on, the RFI was
>horrendous. Gradually I removed them only to find I still had problems.
>While doing some electrical work an electrician found the signal injector
>for the system behind the main breaker panel, and that eliminated nearly all
>the noise.
>
>I should say nearly all the broadband noise, as I was left with birdies
>about every 30 kHz or so. Eventually I tracked those down to a Linksys
>Wireless G router, model wrt54gs. My previous Linksys bit the dust just
>before I moved, so I can't say if I would have heard the birdies from this
>one had I installed it in the old QTH. I have wireless and wired
>connections running off this router, and have helped the problem by
>installing ferrite on the power wart lead and all the data leads. But I
>have not been able to eliminate the rather broad birdies that seem to fall
>at nice dx frequencies.
>
>Has anyone on the reflector had such a problem and found a way to cure it?
>Searching on the internet I find that RFI from routers is a well known
>phenomenon, but I have seen no suggestions for curing the problem.
>
>
>Bob W2WG
>
>
>
>-----Original Message-----
>From: [hidden email]
>[mailto:[hidden email]] On Behalf Of Bob - W5BIG
>Sent: Wednesday, August 10, 2005 9:32 AM
>To: tom.w3qs; 'Elecraft Reflector'
>Subject: Re: [Elecraft] Interference from Computers
>
>Hi Tom,
>
>One major source of noise is the CRT monitor. It helps to make the screen
>display as uniform as possible, like a blank window or a plain background
>without texture.
>
>73/ Bob - W5BIG
>
>
>----- Original Message -----
>From: "tom.w3qs" <[hidden email]>
>To: "'Elecraft Reflector'" <[hidden email]>
>Sent: Wednesday, August 10, 2005 7:03 AM
>Subject: [Elecraft] Interference from Computers
>
>
>> Good Morning Group,
>>
>> I am back on the air (4991) after nearly 20 years. The first thing I
>> noticed was all the interference on 20 meters. Hetrodynes everywhere!
>> What's going on?
>>
>> Took me a while to figure out that it was the computer - not there 20
>years
>> ago!
>>
>> So, other than removing it from the shack (ghastly thought) is there any
>> font of wisdom on this subject or general guidance?
>>
>> Thanks and 73,
>>
>> Tom, W3QS
>>
>>
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com
>>
>
>
>_______________________________________________
>Elecraft mailing list
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>
>
>_______________________________________________
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ROBERT CARROLL-4

RE: Interference from Computers-Routers

In reply to this post by roncasa

Hi, Ron-

The "smart home" system was pretty elderly, having been installed about
1983, two owners back. The house has an alarm system, and when a sensor
detected an intruder, it generated a coded output signal which went to the
box hidden behind the breaker panel. The box in their generated a 2 part
code that was put on a house wiring carrier signal and injected at the
panel. The signal went throughout the house on the ac wiring and when it
reached a "smart switch" with the right unit code and house code (maybe they
were worried about doing things by mistake in the house next door) the
switch would turn on a light in the vicinity of the suspected intrusion.
Actually several signals would be sent so that several lights would be
turned on. There were little bar slides on most of these switches allowing
you to turn off the remote feature if you wanted. We also discovered a
little remote control allowing you to turn on things remotely if you wanted.
Some of the smart switches included a dimmer which could be operated by the
remote control. It was the dimmer capability that caused me to send several
things to the dump. The dimmers were designed for incandescent lights only
drawing 500w or less, but the original electrician had wired them to the
upper socket in many ac outlets. I guess the idea was to going into a room,
hit the wall switch and use the dimmer to control table lamps plugged into
the upper outlets. But the dimmer was never designed to handle fluorescents
or switching power supplies, and I destroyed several things before finding I
wanted to dump the "smart" system.

Bob W2WG

-----Original Message-----
From: ron [mailto:[hidden email]]
Sent: Wednesday, August 10, 2005 10:31 AM
To: ROBERT CARROLL
Cc: 'Elecraft Reflector'
Subject: Re: [Elecraft] Interference from Computers-Routers

Wow, good work Bob.
Thank you for sharing it with us. I made my wife throw out all (2) the
touch lamps and removed all "dimmer" switches. (It makes the radio
"dim") but never thought about the router causing birdies that I do have
(always on your favorite freqs).
Can you explain what the signal injector behind the panel was for?
Ron wb1hga
(still not entirely noise free, yet)

ROBERT CARROLL wrote:
> I have recently moved to a new QTH and am slowly getting things in shape
to
> get back on the air. I ran into a lot of nasty RFI problems. The
previous
> owner had installed "smart house" wall switches throughout the house.
They
> were supposed to control incandescent lamps only, but in fact they
> controlled fans, wall outlets, etc. Besides sending a few entertainment
> radios to the dump before I figured out what was going on, the RFI was
> horrendous. Gradually I removed them only to find I still had problems.
> While doing some electrical work an electrician found the signal injector
> for the system behind the main breaker panel, and that eliminated nearly
all

> the noise.
>
> I should say nearly all the broadband noise, as I was left with birdies
> about every 30 kHz or so. Eventually I tracked those down to a Linksys
> Wireless G router, model wrt54gs. My previous Linksys bit the dust just
> before I moved, so I can't say if I would have heard the birdies from this
> one had I installed it in the old QTH. I have wireless and wired
> connections running off this router, and have helped the problem by
> installing ferrite on the power wart lead and all the data leads. But I
> have not been able to eliminate the rather broad birdies that seem to fall
> at nice dx frequencies.
>
> Has anyone on the reflector had such a problem and found a way to cure it?
> Searching on the internet I find that RFI from routers is a well known
> phenomenon, but I have seen no suggestions for curing the problem.
>
>
> Bob W2WG
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bob - W5BIG
> Sent: Wednesday, August 10, 2005 9:32 AM
> To: tom.w3qs; 'Elecraft Reflector'
> Subject: Re: [Elecraft] Interference from Computers
>
> Hi Tom,
>
> One major source of noise is the CRT monitor. It helps to make the screen
> display as uniform as possible, like a blank window or a plain background
> without texture.
>
> 73/ Bob - W5BIG
>
>
> ----- Original Message -----
> From: "tom.w3qs" <[hidden email]>
> To: "'Elecraft Reflector'" <[hidden email]>
> Sent: Wednesday, August 10, 2005 7:03 AM
> Subject: [Elecraft] Interference from Computers
>
>
>
>>Good Morning Group,
>>
>>I am back on the air (4991) after nearly 20 years. The first thing I
>>noticed was all the interference on 20 meters. Hetrodynes everywhere!
>>What's going on?
>>
>>Took me a while to figure out that it was the computer - not there 20
>
> years
>
>>ago!
>>
>>So, other than removing it from the shack (ghastly thought) is there any
>>font of wisdom on this subject or general guidance?
>>
>>Thanks and 73,
>>
>>Tom, W3QS
>>
>>
>>_______________________________________________
>>Elecraft mailing list
>>Post to: [hidden email]
>>You must be a subscriber to post to the list.
>>Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>>
>>Help: http://mailman.qth.net/subscribers.htm
>>Elecraft web page: http://www.elecraft.com
>>
>
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>
> _______________________________________________
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> Post to: [hidden email]
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>

Leigh L. Klotz Jr WA5ZNU

Re: Interference from Computers

Administrator

In reply to this post by tom.w3qs

There is a discussion about Ethernet carriers going on on RFI list at
Contesting. I am about to try using 10 mbit multimode fiber, which
though slow, is fast enough for external links, which are the longest
runs. Using shielded cat5 for the short runs of 100MBit Ethernet seems
to help those, though some radiation occurs from the router and hub and
switch boxes, and their infernal switching power supplies.
Leigh / WA5ZNU
On Wed, 10 Aug 2005 5:04 am, tom.w3qs wrote:

> Good Morning Group,
>
> I am back on the air (4991) after nearly 20 years. The first thing I
> noticed was all the interference on 20 meters. Hetrodynes everywhere!
> What's going on?
>
> Took me a while to figure out that it was the computer - not there 20
> years
> ago!
>
> So, other than removing it from the shack (ghastly thought) is there
> any
> font of wisdom on this subject or general guidance?
>
> Thanks and 73,
>
> Tom, W3QS
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

Dan Barker

RE: RE: Interference from Computers-Routers

In reply to this post by Mark J. Schreiner

The Linksys devices have the switching in the wart, not the box. You can put
it on a 6-v dry cell for testing. (Check, some Linksys are 12v, most are 5).

Dan / WG4S / K2 #2456

<snip>
That is assumming they are coming from the wall wart if the switching supply
is built into it, as compared to if the switching part is in the router
itself.
</snip>

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Kevin Wood-7

RE: Interference from Computers-Routers

In reply to this post by ROBERT CARROLL-4

>> Has anyone on the reflector had such a problem and found a way to cure
>> it?
>> Searching on the internet I find that RFI from routers is a well known
>> phenomenon, but I have seen no suggestions for curing the problem.

FWIW I found that using shielded twisted pair (STP) ethernet cables rather
than the more common unshielded twisted pair (UTP) helps. STP cables have
a foil shield over the pairs of cable which is grounded to the equipment
chassis by a metal outer on the RJ45 connector.

It's still worth putting a ferrite on each end of the cable.

I've got a Draytek broadband router that puts out loads of QRM right over
the HF bands and beyond 2m. When I had a look inside I found it's got a
PCB containing a switching regulator, a fast CPU and the line transceiver
for the ADSL. This just sits inside a plastic box with no attempt at
screening whatsoever. I think the fix is going to be to put the whole lot
into a larger metal box and filter the connections in and out.

Needless to say, a product to avoid if you value a quiet electrical
environment!

Putting a wireless LAN router in a metal box probably defeats the object
of having it, unless you can wire the antenna to an SMA connector on the
outer box, I suppose.

Finally another source of noise I find is video cables connecting cable /
satellite set top boxes to TVs. Here you get a signal with strong 50 / 100
Hz components (OK. 60/120Hz for most of you I guess!) that varies in
amplitude with the brightness of the picture.

Hi to all (first post here). K2 kit on order...

Kevin
G7BCS

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tom.w3qs

Computer Interference Redux

Well, I knew it wouldn't be easy.

Thanks to all who responded.

After a couple of hours plugging and un-plugging, I have found that nearly
all my interference comes from the CRT and from my internet stuff in the
next room - modem, wireless router and switch. Don't know where the rest is
coming from.

Easy to replace the CRT with an LCD panel but the internet stuff is going to
be more of a challenge.

At least now I know where to look.

Thanks, es 73,

Tom - W3QS

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S55M

Re: Interference from Computers

In reply to this post by Leigh L. Klotz Jr WA5ZNU

Drastical measures:
http://www.sm5bsz.com/linuxdsp/hware/quietpc.htm

73's
de
S55M Nr3204
----- Original Message -----
From: "Leigh L Klotz, Jr." <[hidden email]>
To: "tom.w3qs" <[hidden email]>; "Elecraft Reflector"
<[hidden email]>
Sent: Wednesday, August 10, 2005 5:05 PM
Subject: Re: [Elecraft] Interference from Computers

> There is a discussion about Ethernet carriers going on on RFI list at
> Contesting. I am about to try using 10 mbit multimode fiber, which
> though slow, is fast enough for external links, which are the longest
> runs. Using shielded cat5 for the short runs of 100MBit Ethernet seems
> to help those, though some radiation occurs from the router and hub and
> switch boxes, and their infernal switching power supplies.
> Leigh / WA5ZNU
> On Wed, 10 Aug 2005 5:04 am, tom.w3qs wrote:
> > Good Morning Group,
> >
> > I am back on the air (4991) after nearly 20 years. The first thing I
> > noticed was all the interference on 20 meters. Hetrodynes everywhere!
> > What's going on?
> >
> > Took me a while to figure out that it was the computer - not there 20
> > years
> > ago!
> >
> > So, other than removing it from the shack (ghastly thought) is there
> > any
> > font of wisdom on this subject or general guidance?
> >
> > Thanks and 73,
> >
> > Tom, W3QS
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
> > http://mailman.qth.net/mailman/listinfo/elecraft
> >
> > Help: http://mailman.qth.net/subscribers.htm
> > Elecraft web page: http://www.elecraft.com
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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>
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

roncasa

Re: Interference from Computers

Gee, thats an awful lot of work to filter computer noise.
The alternative I suppose, is move the desk top PC in the cellar, then
run l-o-n-g cables for a mouse, keyboard and flat screen monitor (LCD?).
(smile)
My favorite hobby is ham radio over computers. If a problem is caused by
a PC...guess which item I would dump. (heh heh)

S55M wrote:
> Drastical measures:
> http://www.sm5bsz.com/linuxdsp/hware/quietpc.htm
>

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John [K7SVV]-2

Re: Interference from Computers-Routers

In reply to this post by ROBERT CARROLL-4

Robert,
Like you, most of my interference comes from a LINKSYS WRT54G.I
have tried unsuccessfully to use ferrite cores on both ends of the
power cord. The birdie that hurts me the most is at 14.333 MHz. I
have been thinking about switching to a D-LINK router because I have
heard that it is much quieter.

John [K7SVV]

On 8/10/05, ROBERT CARROLL <[hidden email]> wrote:

> I have recently moved to a new QTH and am slowly getting things in shape to
> get back on the air. I ran into a lot of nasty RFI problems. The previous
> owner had installed "smart house" wall switches throughout the house. They
> were supposed to control incandescent lamps only, but in fact they
> controlled fans, wall outlets, etc. Besides sending a few entertainment
> radios to the dump before I figured out what was going on, the RFI was
> horrendous. Gradually I removed them only to find I still had problems.
> While doing some electrical work an electrician found the signal injector
> for the system behind the main breaker panel, and that eliminated nearly all
> the noise.
>
> I should say nearly all the broadband noise, as I was left with birdies
> about every 30 kHz or so. Eventually I tracked those down to a Linksys
> Wireless G router, model wrt54gs. My previous Linksys bit the dust just
> before I moved, so I can't say if I would have heard the birdies from this
> one had I installed it in the old QTH. I have wireless and wired
> connections running off this router, and have helped the problem by
> installing ferrite on the power wart lead and all the data leads. But I
> have not been able to eliminate the rather broad birdies that seem to fall
> at nice dx frequencies.
>
> Has anyone on the reflector had such a problem and found a way to cure it?
> Searching on the internet I find that RFI from routers is a well known
> phenomenon, but I have seen no suggestions for curing the problem.
>
>
> Bob W2WG
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bob - W5BIG
> Sent: Wednesday, August 10, 2005 9:32 AM
> To: tom.w3qs; 'Elecraft Reflector'
> Subject: Re: [Elecraft] Interference from Computers
>
> Hi Tom,
>
> One major source of noise is the CRT monitor. It helps to make the screen
> display as uniform as possible, like a blank window or a plain background
> without texture.
>
> 73/ Bob - W5BIG
>
>
> ----- Original Message -----
> From: "tom.w3qs" <[hidden email]>
> To: "'Elecraft Reflector'" <[hidden email]>
> Sent: Wednesday, August 10, 2005 7:03 AM
> Subject: [Elecraft] Interference from Computers
>
>
> > Good Morning Group,
> >
> > I am back on the air (4991) after nearly 20 years. The first thing I
> > noticed was all the interference on 20 meters. Hetrodynes everywhere!
> > What's going on?
> >
> > Took me a while to figure out that it was the computer - not there 20
> years
> > ago!
> >
> > So, other than removing it from the shack (ghastly thought) is there any
> > font of wisdom on this subject or general guidance?
> >
> > Thanks and 73,
> >
> > Tom, W3QS
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
> > http://mailman.qth.net/mailman/listinfo/elecraft
> >
> > Help: http://mailman.qth.net/subscribers.htm
> > Elecraft web page: http://www.elecraft.com
> >
>
>
> _______________________________________________
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>
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>
>
> _______________________________________________
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>

Paul Gates

Re: Interference from Computers-Routers

This is all interesting about the interference. I have my computer about 3
inches from my station and have never had any noise or interference from it.
I have the same router that you mention and not one peep of noise from it.
Am I just lucky?
Paul
Paul Gates
K1 #0231
KX1 #1186
XG1
[hidden email]

----- Original Message -----
From: "John [K7SVV]" <[hidden email]>
To: "ROBERT CARROLL" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Sent: Wednesday, August 10, 2005 3:11 PM
Subject: Re: [Elecraft] Interference from Computers-Routers

Robert,
Like you, most of my interference comes from a LINKSYS WRT54G.I
have tried unsuccessfully to use ferrite cores on both ends of the
power cord. The birdie that hurts me the most is at 14.333 MHz. I
have been thinking about switching to a D-LINK router because I have
heard that it is much quieter.

John [K7SVV]

On 8/10/05, ROBERT CARROLL <[hidden email]> wrote:

> I have recently moved to a new QTH and am slowly getting things in shape
> to
> get back on the air. I ran into a lot of nasty RFI problems. The
> previous
> owner had installed "smart house" wall switches throughout the house.
> They
> were supposed to control incandescent lamps only, but in fact they
> controlled fans, wall outlets, etc. Besides sending a few entertainment
> radios to the dump before I figured out what was going on, the RFI was
> horrendous. Gradually I removed them only to find I still had problems.
> While doing some electrical work an electrician found the signal injector
> for the system behind the main breaker panel, and that eliminated nearly
> all
> the noise.
>
> I should say nearly all the broadband noise, as I was left with birdies
> about every 30 kHz or so. Eventually I tracked those down to a Linksys
> Wireless G router, model wrt54gs. My previous Linksys bit the dust just
> before I moved, so I can't say if I would have heard the birdies from this
> one had I installed it in the old QTH. I have wireless and wired
> connections running off this router, and have helped the problem by
> installing ferrite on the power wart lead and all the data leads. But I
> have not been able to eliminate the rather broad birdies that seem to fall
> at nice dx frequencies.
>
> Has anyone on the reflector had such a problem and found a way to cure it?
> Searching on the internet I find that RFI from routers is a well known
> phenomenon, but I have seen no suggestions for curing the problem.
>
>
> Bob W2WG
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bob - W5BIG
> Sent: Wednesday, August 10, 2005 9:32 AM
> To: tom.w3qs; 'Elecraft Reflector'
> Subject: Re: [Elecraft] Interference from Computers
>
> Hi Tom,
>
> One major source of noise is the CRT monitor. It helps to make the screen
> display as uniform as possible, like a blank window or a plain background
> without texture.
>
> 73/ Bob - W5BIG
>
>
> ----- Original Message -----
> From: "tom.w3qs" <[hidden email]>
> To: "'Elecraft Reflector'" <[hidden email]>
> Sent: Wednesday, August 10, 2005 7:03 AM
> Subject: [Elecraft] Interference from Computers
>
>
> > Good Morning Group,
> >
> > I am back on the air (4991) after nearly 20 years. The first thing I
> > noticed was all the interference on 20 meters. Hetrodynes everywhere!
> > What's going on?
> >
> > Took me a while to figure out that it was the computer - not there 20
> years
> > ago!
> >
> > So, other than removing it from the shack (ghastly thought) is there any
> > font of wisdom on this subject or general guidance?
> >
> > Thanks and 73,
> >
> > Tom, W3QS
> >
> >
> > _______________________________________________
> > Elecraft mailing list
> > Post to: [hidden email]
> > You must be a subscriber to post to the list.
> > Subscriber Info (Addr. Change, sub, unsub etc.):
> > http://mailman.qth.net/mailman/listinfo/elecraft
> >
> > Help: http://mailman.qth.net/subscribers.htm
> > Elecraft web page: http://www.elecraft.com
> >
>
>
> _______________________________________________
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>
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--
John [K7SVV]
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Stuart Rohre

Re: Interference from Computers-Routers

Maybe Paul, you have a better grounding scheme.
Part of good grounding, is to run a computer used with a radio from the same
power strip. IF the computer is NOT used with radio, have it separated or
on different power circuit.

Stuart
K5KVH

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Earl W Cunningham

Re: Interference from Computers-Routers

In reply to this post by ROBERT CARROLL-4

Paul, KD3JF wrote:

"I have my computer about 3 inches from my station and have never had any
noise or interference from it. I have the same router that you mention
and not one peep of noise from it. Am I just lucky?"
==========
My guess is that your antenna is coax-fed and is more than just a few
feet from your computer.

We must keep in mind that the RFI generated by the switching power
supplies in a computer system enters the ham receiver via the receiver's
antenna input. Those using well-matched coax-fed antennas are probably
bothered very little by this type of RFI. But those whose antennas come
into an antenna tuner located in the shack are probably more cognizant of
the problem.

73, de Earl, K6SE
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