Hi,
I have not tried this, as I was trying using a device that properly handled making a half duplex setup, but How I read this was:
TX ----1K Resistor------+----------To Servos
RX-----------------------+
That is there is a 1K resistor between the TX line and the servos, and the RX line is directly connected to the servos.
Again I have not tried, but that is how I read it and it made some sense. This helped the receiving of data back from the servos as the TX line was probably still in a high state, but through the resistor it acted more like a Pull up resistor, which the servos could still pull low when needed...
Kurt