[CQ-Contest] 10BaseT vs 10Base2 Summary

[Jim Rhodes]

I hav always used 10Base2 cabling for the network here at home in the 
belief that it would suffer/cause less RFI. I am now contemplating 
switching to a cable modem type of internet access and will have to have at 
least some 10BaseT in the house. What has been the experience of the group 
with 10BaseT networking. Have there been more problems with RFI with this 
type of cable or am I worried about nothing.

As it stands now I could just run a length of coax accross the house to the 
entry point of the system (25-30 ft) and leave the 10Base2 in place. Or I 
could run CAT5 cable over to the entry point from a hub in the shack and 
plug into the 10Base2 network there. Or I could just convert to 10BaseT for 
the all three computers. With the hub either in the shack or the utility 
room where the entry point will be. I think I would only have to replace 1 
card if I did that or none if I kept the 10Base2 setup.

As usual, I will summarize if there is interest. Thanks.

Jim Rhodes K0XU
rhodes at willinet.net

__________________________________________________________________________

 From K1TTT:


some users of nettsr have reported rf getting into 10baset cables or hubs.  i
have had no trouble with 10base2 here either from rf getting in or noise 
getting
out.

 From W2UP

Hi Jim,
I asked the same question several months ago, so you may want
to check the archives for details. In summary, everyone using Cat5
cable said they had no RFI probs.
I have a hybrid system here. Rather than rewire the shack and get
new NICs (mine are olides that have a BNC connector only, not a
combo card). I kept the coax connecting 2 computers in the shack
(using a 4 port Netgear hub which has a single BNC port and 4
RJ45 ports), and use Cat5 for the upstairs computer and link to the
DSL Router (this part currently under construction).
No RF probs in either direction.
GL/Barry


 From N4ZR


no problems with Cat 5 here -- my shack computer is on the network, running
at 10 MHz, and I have about 100 feet of Cat 5 deployed.  I *think* I would
notice any ham band RFI.


 From N5NJ

I'm running 10-baseT  here with 4 computers all over the house and
have no interference whatsoever.

We also installed 10-baseT in the shack at V26B in Antigua and have no
trouble with it there either.

You may want to get a hub that supports both coax and twisted pair to
eliminate the need to re-wire your house.  I am using such a hub here
because it was cheap and just don't use the coax port.

Bob

 From K0WA

I work in a hospital with a lot of radiation moving around the area.  We
have a CAT scanner, numerous xray machines, nuclear photography, and we
even had a accelerator on the campus to treat tumors at very high doses of
radiation. Plus, we have gobs and gobs of low power telemetry and a 50 watt
VHF radio for the amulance.

I use CAT5 10base-T wire everywhere.  No problems at all.  I really do not
like coax because coax can be ssuseptable to common mode interference...at
least that has been my thinking.  So, all of the coax is gone. To me, coax
is an unbalanced line which RF can ride the shield.

In 10base-T CAT 5 wire, the eight wires are twisted a certain amount per
inch.  Each pair is twisted and then the pairs are twist again.  The
concept here is cancelation opf any type of radiation in or out of the
wire.  If you look at the physics...the twisted wire cancels any kind of
magnetic field due to the phyisics of magnatism.  Also, 10base-T is
balanced without a "ground" so you won't get common mode interference.  So,
go with the wire....

Lee

 From WN2A

10B2 networks are now legacy networks.  And good riddance!  They are plagued
with bus termination problems and simply don't scale.  One bad connection in
the chain can take the whole network down.  And, because no one really wants
them any more, they cost much more!  Cat 5 cabling as used in 10BT, 100BT,
and now 1000BT networks (yup, gigabit over copper is easily available and
will cost less than $100 per port by next summer) is very noise immune.
Remember, the cable is several twisted pair.  I've had no problems
whatsoever at my home where I have an extensive home network and run a KW
(ICOM 781/4KL) on HF and have dabbled some with high power UHF/VHF.  Nor is
there any network generated noise into any receiver.  CAT 5 cabling is easy
and cheap to configure, hubs and unmanaged switches are nearly free and just
about bullet proof - I've never had a hub failure EVER and have had only a
single instance of an unmanaged switch going off into la-la land.  Netgear
stuff is highly recommended - and their enclosures are metal, not plastic
giving you, perhaps, some re-assurance about RFI immunity.

 From N1CC


Have been using 10BaseT CAT-5 wiring with the line going from the basement to
the third floor parallel to the tower for 2 years with no interference either
way.  In South Carolina the antennas are in the attic and the cable modem is
in the FROG (Finished Room Over Garage) surrounded by the antennas, and runs
all the way across the house with 100 feet of CAT 5 to the wife's computer,
and no problem.

In Albany - the first setup - I ran 1500W here in SC indoor antennas 100W

http://members.aol.com/n1cc

It's cheaper to let the cable company supply you with the 10BaseT cards for
the one PC and then use a "hybrid" hub that either has a BNC as well as
several 10BaseT slots....then it would be to use 10Base2 to 10BaseT
transceivers.

The 10Base2 was floating over ground, you can't ground 10Base2 cable and the
signaling rate of 10 MHz would probably produce more problem than the two
twisted pairs in UTP unshielded CAT 5.  You could go for shielded CAT 5, it's
not grounded either....and the experience I have is that from 160-2 M you
don't have a problem.

73, Jim   (Oh, I work for Cisco Systems - and Retired from Motorola - been
working with Ethernet and the IEEE 802.X versions since it came out)

 From Robert Brandon

I don't have any direct experience with RF, but I do know that not all CAT5
is created equal.  Avoid the Home Depot grade, and go with at name you know
(e.g., Belkin).  I'm pretty sure you can get shielded CAT5, too, which
should be comparable to the 10Base2.

from K7FR


I had both in my last house and experienced no problems.

As an aside; how much are they charging for cable access?  Is it a true
digital system and are they using fiber to the converter box?  The local
cable company is busily installing fiber in my neighborhood but won't say
how much it's going to cost to connect.


_________________________________________________________________________


Well, think I have decided for now to run CAT5 cable from the shack to the 
entry point with a hub in the shack. I picked up a 16 port hub real cheap 
and already have 2 BNC only NICs and 1 combo NIC. The opinions seem to be 
in favor of CAT5 cable.

As to the cost, ths first company I talked to quoted me $45/month and they 
furnish the equipment. It is actually a wireless device.that downloads at 
2.5G and uploads at 2.1G. The company I was talking to refers to it as a 
"cable modem". They also sell MMDS cable TV. This gives you "always on" 
internet at 128K and a static IP address.
Jim Rhodes K0XU
rhodes at willinet.net


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