Topband: 2Wire, Inc. 3800HGV-B Gateway. RFI --Problem fixed for now….

Guy Olinger K2AV olinger at
Sat Feb 4 15:15:46 PST 2012

The CAT5 in question for the interference is the INPUT side of the gateway
box.  This is sometimes used from the loop termination on the side of the
house somewhere to the gateway box.  THAT was the CAT5 sensitive to the
ferrites.  Ethernet on the output side of the gateway has not been an
issue.  Just the input where the content is 0.2 to 8 point something MHz.

On Sat, Feb 4, 2012 at 10:57 AM, Frank Davis <fdavis at> wrote:

> In reply to Jim:
> The CAT5 cable used with the 3800 modem is the one that came in the box
> with it.  The cable is very small diameter and very flexible...the modular
> plugs on it are smaller then the other plugs I have here on what i call
> regular CAT5 cable. The regular CAT5 modular plugs will not plug unto the
> jack on the modem.
> When that small flexible cable was wound on  the two stacked toroids that
> I used It was twisted in a couple of  places so maybe that contributed to
> the FEC events being seen by the telco test equipment.  The cable appears
> to be very cheap and a minimal attempt by the manufacturer to provide a
> cable for general use ...certainly not robust.
> The toroids are not on this line now and all seems to be working fine.
>  The iMAc download speed testing within the BellAliant network is 6.6 mbps.
>  The full capacity of the line is supporting 4 IPTV set-top boxes two of
> which are HD.
> Fibre Op coming within a few months to my area!
> Frank VO1HP
> > The BellAliant technician told me that placing the ferrites on the CAT5
> > feeding the modem caused  a significant number ( hundreds of '000's on a
> > continual basis.) of FEC (forward error correction) events to begin
> happening
> > on my line.
> That does not make sense unless the CAT5 was mechanically distorted by
> the winding.  That would disturb the impedance at bit, but a LOT of
> errors doesn't make sense to me. The ferrites form a common mode choke,
> which the differential circuit should not see.
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK

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