Loop thru works ok if surfing for channels on the same polarisation.<br /><br />If you loop through from the TARBS box to another FTA box, the FTA box won't be able to watch ERT (on the vertical pol) as the TARBS box has switched the LNB to the UBI channels (which are on the horizontal pol). The LNB can only switch 1 pol at a time. Thats why Lazersat uses the Dreambox to switch poles on the LNB.<br /><br />To overcome this issue a dual output LNB needs to be used where you run a cable to each IRD