One vote for transceiver from me too, if you have AUI port. I have Hydra's Amiganet 1.1 card with one AUI and two BNC connectors. At first I used hub with BNC, but then picked handful of AUI->RJ45 transceivers from recycling center for free and those were so much more comfortable to use

Remember to check your ethernet card if there's jumpers to change when using AUI... in Hydra you had to switch whole line of them.