CAT5 Fast Cheap Digital

[moffy]

If you want to send a reasonably high speed digital signal several metres cheaply this simple and cheap CAT5 transmitter and receiver worked at 50MHz over 50m, transmitting then receiving back a 50MHz square wave.
The obvious solution is to use an LVDS Tx and Rx, but I opted for a 74ALVC14 inverter to get extra signal level as the LVDS drivers have a limited voltage swing. Some speed up capacitors C1,C2 have been included, if needed, to help compensate for cable capacitance, but for the 50m of CAT5e in my test it wasn't necessary.
There is provision for a simple POE which in this case should be limited to about 5V. Various jumpers are included which select what pair the Tx and Rx are on as well as selecting POE or not. It's a simple circuit, but might be handy in certain cases.