[RFI] Ethernet, radio astronomy, and electric fences

[William Liporace - NA2NA]

Hi Folks,
I am not an RFI expert, but I do work a lot with Ethernet products... Over
the last couple of years I have been a part of network design and layout.
There is a lot to learn, know and understand!!

First is the cable....
CAT3 is basically a 10 MB wire loosely twisted pair. They are greatly
affected by EMI and other problems. I have even seen networks done with
regular twisted telephone wire!!

CAT5/5E is basically 100MB wire twisted tighter. This is good to 300 meters.
and is less affected by EMI. This is also offered in solid and stranded
wire. There are different connectors for the different wire. Also remember
there is also plenum, for running in ceilings ands duct work.... This can
come shielded.....

CAT 6 is the new craze/standard. This will do 1000 MB and still stuck to the
300 meter range. This is usually run with special connectors, jacks and
equipment.... I have seen professionally made wire test bad!

Please remember that there are MANY reasons for EFI/EMI from Ethernet. I
have seen bad wall warts, bad p/s in the units, bad NICs and kinks in the
wire that you can not see (till you strip the shields off.

In my house, I have run all CAT 5 wire. I have Netgear, Linksys, Belkin
other gear laying around. I find a lot of other stuff causing the problem.
There is always a bad unit, Heck I have a couple of those laying around
too!!

FYI...  If you want to get a product that has a REAL warranty... Buy 3Com...
they offer a "lifetime warranty" that they actually support!!  I have
replaced 5+ yr old gear for the cost of one way shipping!!

GL Will NA2NA
na2na.net an AR-Cluster Node!