Not sure it's what I wanted anyway, was especially interested in what "fss stacked lnb" means and how it might be applied to FTA, if at all.
The SuperDishes and their components can be useful for FTA. It sounds like the one you have was for receiving the DN 110, 119 and 121 birds. There was an alternate model for DN 105, 110 and 119. The reason for the weird looking feed you mentioned is the difficulty of receiving the closely spaced 119 and 121. From a FTA perspective, a SuperDish will have a sensitivity in the 70 cm range, which isn't incredible. However it does have a better ability than typical offsets to receive multiple satellites.
What I particularly like about these dishes are the FSS LNBs. While the 110 and 119 LNBs are pretty much only useful for receiving circularly polarized DBS satellites, the 105 and 121 LNBs are designed to receive linearly polarized Ku signals in the standard North American bands. The feeds are rather marginal, but the LNBs turn out to be of good quality (coincidentally I started
this thread a few days ago on some of the technical aspects of these units).
The point of bandstacked LNBs is to pass both H & V polarizations on the same cable. Typical FTA LNBs will send only H or V from 950-1450 MHz, depending on the commanded voltage (18V = H, 13V = V). The SuperDish LNBs send V from 950-1450 MHz, and H from 2150-1650 MHz (the spectrum is inverted). This isn't that useful if you only have one LNB and one receiver, but it becomes very nice if you have more than one of either or both.
If you have multiple receivers, you will need only one downlead coax and a splitter to connect all the receivers. Because H & V are on the same cable, any receiver can get to either polarization. Without a bandstacked LNB, you would need either a multi-output LNB and/or switches to make this work. If you have multiple LNBs, particularly feeding multiple receivers, the use of bandstacked LNBs will cut the number of cables and switches in half.
It's not a completely free ride because bandstacked LNBs put a higher premium on quality components because the highest frequency they send is 700 MHz higher than a typical LNB. Also some receivers are not well set up to work with bandstacked LNBs, although there are usually workarounds. Nevertheless in anything but a very simple system, bandstacked LNBs can be very nice to have.
