Three tuners with two LNB feeds - loop through query

[aido]

I took a punt on one of the LX3s from WoS this week and I'm just setting it up tonight but I'm confused around the loop through settings.

Basically I've got the three DVB-S tuners in there and I've got two feeds coming from the LNB connected to the in ports of tuners A & B.

I've then connected the output of tuner A to the input of tuner C.

Tuners A & B are configured in simple mode and both pointing at 28.2E and none, and Tuner C is in loop through mode and is configured as connected to Tuner A.

If I use Sat Finder it only shows me Tuners A & B as being available and from testing I can only playback two channels at once - I can't actually get three playing at the same time.

I'm just trying to work out how this should work - if I try and playback a channel on the same transponder as tuner A on tuner C that should let me get three streams shouldn't it?

The manual only shows loop through being used with one LNB feed to tuner A with the loopback cable then connected to the input of tuner B - should I be doing that with the separate feed into tuner C?

I tried changing tuner C so that it is configured the same as A & B and it seems to find channels fine in sat finder etc (as they all do and lock ok etc).

Thanks in advance