Thin Ethernet to RJ45

I am helping a friend update his computers and network. Current net is 2 Win95 machines connected via thin ethernet coax running Netbeui NE2000 compat network cards. He is replacing one computer to a new one that will run Windows XP and has a 10/100 RJ45 NIC built in. The older machine we want to keep in place - or perhaps upgrade to Win98SE. The cable run is one I would prefer not to mess with. Up a floor and down a hallway and embedded in the walls - so not too easy to pull CAT5 replacing the thin ethernet. I'd rather just get everything up on CAT5 10/100 NICs running TCP/IP and find a way to interface the thin ethernet cable to the RJ45 connectors on new NICs. I used to connect 3270 terminals to 3270 terminal controllers via twisted pair by using 'baluns' to convert coax to twisted pair - but I'm sure this is a different game - but similiar. Can this be done? Tried searching Blackbox and nothing so far.
Thanks!
By the way - great site and a lot of other great FAQ's etc. I'm sure I'll come up with more issues with the new Win XP beast that I am about to wrestle with. Win95 and Win98 has been my bread and butter and can usually hack through that.

1. RE: Thin Ethernet to RJ45
DJ Net2Infinity Apr-12-02 07:23 PM
In response to message 0

I work with 3270 Controllers as well for the state ( you know how ceehp they are) I actually think you should be able to make a small patch cord and use a balun.
Plug the patch cord into the nic card then into the balun, you will have to get a gender bender for the end of the balun to connect to your coax, but it should work I see no reason why it shouldn't. I'll try to do some reseach and get back to ya.

2. RE: Thin Ethernet to RJ45
DJ Net2Infinity Apr-12-02 08:33 PM
In response to message 1

On Second thought strike that, you would end up with double the impedance ... the balun is used to give you a 70ohm load and that wont work to well.
Back to the drawing board.
Why can't you just put that card in the new machine though?

3. RE: Thin Ethernet to RJ45
lbyard Apr-13-02 00:04 AM
In response to message 2

You could buy a BNC/RJ45 NIC for the new computer, if you can find one. Those who know me know what I'll say next: run a new cable. That shouldn't be difficult as you can pull it with the old one. Now, when you pull that new cable, also pull some strong nylon sting with it and leave it in the wall... Larry

4. RE: Thin Ethernet to RJ45
aschoeller Apr-13-02 05:13 PM
In response to message 2

Thanks for your replies - the board is ISA and the new machine is PCI only - so we struck out on that one.

5. RE: Thin Ethernet to RJ45
lbyard Apr-13-02 08:30 PM
In response to message 4

There are PCI combo adapters. Larry

6. RE: Thin Ethernet to RJ45
Twinhead Apr-22-02 04:17 PM
In response to message 0

To connect COAX directly or via a Balun to UTP is Impossible!
UTP uses Duplex channels in two pairs.
Four if the eight wires are used.
Coax uses only two wires (Strictly one, the outer layer is an shielding)
How for god sake connect COAX for any reason directly to UTP??
Buy a "Linkbuilder" or a HUB with BNC AND UTP inputs.
Then (Still only at 10Mbit/s) you can communicate between the UTP leg and the Coax leg of the network.
Victor.