[RFI] Zoom X6 DSL Modem loses internet connection

W0MU Mike Fatchett w0mu at w0mu.com
Mon Mar 2 17:29:54 PST 2009

Just an update on the 40m dsl issue here.  I tried the OK filter and it
might have improved things a bit, however it reduced my bandwidth from 7mb
to 6mb.  So this might not be a solution for broaderband service.

I am now going to work on common mode current issues.

I do believe the Excelsious filter does help on the high bands.  I had taken
it out and my son came over to the shack to complain about internet loss so
I put it back in and no more complaints when I was on 15 and 20.  

All very unscientific findings.  I need to back down to a minimal setup with
a laptop, dsl and nothing else hooked up and start from there.  I got in a
bunch of type 31 ferrite snap ons so hopefully I will get my arms around
this soon.


"A slip of the foot you may soon recover, but a slip of the tongue you may
never get over." Ben Franklin
-----Original Message-----
From: Jim Brown [mailto:jim at audiosystemsgroup.com] 
Sent: Wednesday, February 25, 2009 3:08 PM
To: W0MU Mike Fatchett
Subject: Re: [RFI] Zoom X6 DSL Modem loses internet connection


If you don't find the Excelsus filter useful, would you like to send it to
me so that I can measure it?  I'm working on the EMC chapter for the ARRL
Handbook, and plan to include a few paragraphs on telephone filters. I'll
also post what I learn to my website. 


Jim K9YC

On Wed, 25 Feb 2009 09:47:06 -0700, W0MU Mike Fatchett wrote:

>I tried the Excelsious filter and it does not touch my 40m issue.  
>Their specs say 10mhz and up.  I was hoping they were off a bit.  The 
>filter appears to be well made.  I never noticed problems at those 
>frequencies so it is hard to know if it is doing anything.

>I have ordered the parts to build the OK filter.  I will post my findings.
>Those parts should be in today or tomorrow.

>"A slip of the foot you may soon recover, but a slip of the tongue you 
>may never get over." Ben Franklin -----Original Message-----
>From: rfi-bounces at contesting.com [mailto:rfi-bounces at contesting.com] On 
>Behalf Of Jim Brown
>Sent: Friday, February 13, 2009 10:38 AM
>To: RFI List
>Subject: Re: [RFI] Zoom X6 DSL Modem loses internet connection

>On Fri, 13 Feb 2009 10:04:32 -0700, W0MU Mike Fatchett wrote:

>>Any suggestions on where to start would be appreciated.  It only seems 
>>to happen on 40m.

>You should also call your DSL vendor and tell them that their modem has 
>RFI problems, and ask THEM to fix it. It IS their problem, not yours. 
>W8JI had issues with his modem, and got a replacement that worked.

>Study  http://audiosystemsgroup.com/RFI-Ham.pdf

>If you want to fix it yourself: 

>1) Start with a choke tuned to 40M on each cable connected to the DSL

>2) If that doesn't fix it, leave those chokes in place and add a choke 
>at the Ethernet switch or hub.

>3) I've recently learned of a company in SoCal called Excelsus that 
>sells filters that they say will eliminate RFI to DSL modems. Google to
find them.
>I'm currently writing the EMC chapter for the ARRL Handbook, and called 
>them a week ago for a sample unit so that I could mention them in the 
>Hanbook. So far, no response. There's a more established company in 
>Ohio called KCOM who makes telephone filters that are well known to 
>work very well on telephone lines. It might be worth a phone call to ask if
they have a DSL filter.


>Jim Brown K9YC

>RFI mailing list
>RFI at contesting.com

>RFI mailing list
>RFI at contesting.com

More information about the RFI mailing list