Material Required

One fullduplex Network Interface Card with TP (UTP, RJ-45) interface, manageable in software to set hard 10Mbps full duplex. PCI recommended. A cheap NIC with RTL8139 is a good one. Onboard NICs sometimes have reduced range due to sloppy implemetation of clock separator. ISA cards bring usually reduced speed due to ISA bus limitations. They are also less reliable: ISA bus hasn't gold-plated contacts, PCI has.
Alternatively, you can use a manageable switch that can be set hard to 10Mbps full duplex instead of full-duplex NIC.
If you use unmanageable NIC or switch even at one end of link, the link will always have to run in half duplex mode.
A bunch of big retroreflectors (those big red triangular ones with 15cm side of the triangle) glued with epoxy to a piece of some board. Number necessary for comfortable aiming:
Number of retroreflectors required (those big red triangular with 16cm side)
Distance Retroreflectors

450m 1

800m Car warning triangle

900m 4

1100m 6

1.4km 9

Also a car warning triangle may be used (up to 800m).
200mV-20V digital DC voltmeter or 30mV-20V analogue voltmeter

Tools Recommended

Torque wrench for 17mm or 16mm hex heads (depends on your M10 bolt/screw manufacturer's taste)

You need an operating system and software equipment (user application) that support the following features:

Driver for the network card capable of setting the card into full duplex. Without this, you get just half duplex even with autonegotiation.
Internet Protocol (IP)
Manipulating ARP table. Possibility to establish permament (manual) ARP table entries is required for testing Ronja 10M Metropolis.
Sniffing Ethernet frames or IP packets. Required only for testing.
Setting the NIC into promiscuous mode is required for testing Ronja Tetrapolis.
Automatic repeated sending of ICMP Echo Requests on user's request. Required for testing Tetrapolis. 56-byte and 1400-byte requests are required. 1-second and zero-second delay between consecutive packets must be supported. Cisco-style timing where next packets is sent immediately upon reception of the previous is also highly recommended for the testing.