HF Antenna Connection for LimeSDR-USB

Just getting started.
Will be using Limesdr-usb for HF receiving and I need to know which antenna port on the board do I connect the HF antenna to?

RX1_L or RX1_W or RX2_W (if your app supported second RX). First, read about HF modification:

Great exactly the information I needed. Thank you. Larry