On 7/10/13 7:29 AM, Art Greenberg wrote:
The discussion about protecting networked computers is of interest to me
because I have been thinking about an application here. I thought I'd
start a new thread about my particular situation to see what others think.
I have an enclosed, air conditioned barn that I'd like to put my shack
in. The thinking is, I'd run an Ethernet cable to the house using an
existing buried conduit (that is now empty) and run the radio equipment
remotely. The conduit run is about 230 feet. I figure a total run of 300
feet or so to connect a switch in the barn to a switch in the house. Our
Internet service comes into the house.
use 5.8 GHz WiFi with high gain antennas. Inexpensive bridges
available, etc. 100 meters of airgap is a lot of galvanic isolation<grin>
The barn has its own electric service. There is a shunt-mode "whole
house" surge arrestor installed in the load center. The service feeder
to the barn and the service feeder to the house come from completely
different directions. Both are above ground until they get close.
The antenna transmission lines to the barn would all be run through an
entrance panel with lightning arrestors, bonded to the barn's service
ground. All of the radio equipment would be grounded to the entrance
panel ground. The radio equipment would be very close to the load center.
If I can get a reliable gigabit network running between the barn and the
house, I could put some of my other computer equipment in the barn as well.
Gbit will be hard (impossible) with WiFi (100 Mbps is more like it), but
you might look at some of the point-to-point microwave solutions.
Wireless (where FO cable is "wire") is pretty nice, if you've got a
decent line of sight without too many trees in the way. Some trees are
ok, but dense woods will probably block the signal.
no cables to pull, no worries about the backhoe hitting the conduit, etc.
I'm in Florida, near Gainesville. Lots of lighthing, particularly during
summer.
Long prologue. Now the question.
I think its obvious that fiber would provide complete isolation between
the buildings. But would a copper cable (Cat5e, Cat6) with lightning
arrestors at each end be good enough? What strike scenarios would be
problematic?
100 meters is a pretty long run for copper ethernet (it's at the maximum
distance in the spec). And, by the time you buy and install all the
protective gear you're probably at the point where fiber would have been
cheaper and faster.
if you have overhead utilities now, what about overhead fiber? You can
get sunlight resistant FO cables and since they're non-conductive, you
can string them just about anywhere you want, subject to any other
safety (clothesline height is bad) or aesthetic (No cables across my
backyard, thank you very much) concerns. The stuff is really
lightweight and strong because of that aramid strength member.
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