A suggestion:
Perhaps it is time that Jim posted a little expose on the differences
between common mode and differential mode, as clearly there are
misunderstandings about what CAT5 does and doesn't do with the two modes of
operation.
The fact that CAT5 is wound through several turns on toroids has absolutely
NO EFFECT on the differential mode operation of the twisted pairs!
I guess if the equipment manufacturers/engineers don't understand this,
there is little hope for others in the prevention of common mode
interference both to and from data equipment.
Cheers
Peter VK3QI
----- Original Message -----
From: "Jim Brown" <jim@audiosystemsgroup.com>
To: <towertalk@contesting.com>
Sent: Wednesday, July 18, 2007 3:02 PM
Subject: Re: [TowerTalk] help with interference problems
> On Wed, 18 Jul 2007 00:48:45 -0400, Roger (K8RI) wrote:
>
>>I'd hate to think what'd happen with several turns on a toroid.
>
> No problems anywhere I've used them, and I've used them throughout
> my QTH in Chicago and here in CA. I've recommended them to a lot of
> others, and no reports of problems. Mine were (and still are) on the
> networks that carry traffic for my office, my wife's office, and
> internet radio streaming to me 24/7.
>
> What CAT5 circuits do NOT like is ty-wraping, stapling, and neat
> bundling.
>
> Think about it -- Ethernet hardware has MISERABLE common mode
> rejection, both into and out of the box. Choking those lines kills
> both radiation and reception of trash. On the reception side, that
> means fewer errors and retransmissions. On the radiation side, that
> means less trash on the ham bands.
>
> 73,
>
> Jim Brown K9YC
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|