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Excellent. It worked. Thanks for the help and the formula!

sweet

I knew the formula from awhile ago when I had bandstacked LNB's and a receiver that wouldnt accept an oddball LNB LO frequency. So I kinda lucked out

thats why I thought it was odd for the LNB to be DishPro when you mentioned

I know the repurposed dish / lnbf was old technology sitting on the roof for several years.

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I'm not sure I follow. DishPro is bandstacked and is that and older type or a newer type?

I have two DishNetwork dishes that were left on the roof of a house I bought - one with the LNBF's removed and one with them intact. That's the one I'm using for FTA (until I get a bigger one with a motor). I assumed if I have the bandstacked one, it must "old" from the condition these dishes are in.

badpistacio said:

I'm not sure I follow. DishPro is bandstacked and is that and older type or a newer type?

I have two DishNetwork dishes that were left on the roof of a house I bought - one with the LNBF's removed and one with them intact. That's the one I'm using for FTA (until I get a bigger one with a motor). I assumed if I have the bandstacked one, it must "old" from the condition these dishes are in.

Click to expand...

Badpistacio,

That depends on your reference point.

For DBS technology, bandstacking is now becoming old hat. Dish Network was using this quite a few years ago. I cannot say exactly when they adopted it, but at least prior to 2001.

LNBFs that were predecessors to DishPro and DishPro PLUS LNBFS were referred to as LEGACY LNBFs.

With a LEGACY LNBF, to change between the Vertical and Horizontal transponders, you had to send a DC voltage down the cable to switch the internal oscillator to one mode or the other (13v for vertical and 18v for horizontal).

With DishPro LNBFs, the LNBF is driven by 18v all the time, but there are two oscillators in the LNBF operating at all times, but at different frequencies. One outputs the vertical (or in DN DBS - the RH circular signals) and the other outputs the horizontal (the LH circular signals).

Both polarity signals are available on the same cable at the same time, but they are separated from eachother because their frequencies are unique to eachothers "bands". One band is stacked above the other, hence, band-stacked.

This has an advantage when using multiple receivers as both frequencies (or both vertical and horizontal signals) are available on the cable at all times and any receiver can just pick them off at will. So one cable run can be used for two receivers or one cable run for a dual tuner receiver.

There is more to the whole story than this, because DN's advanced DishPro LNBFs incorporated multiple LNBFs and internal switching so that you not only could get both polarities on one cable, but more than one satellite, as well.

The main advantage of band-stacking was simply less cable to run into a home. Fewer separate cables were required and they could actually reach further distances from the receiver, so a longer cable could be used to reach a more optimum installation point for the dish.

I am being rather vague with this information - there is mouch more to it, but it should provide a basic foundation and if you want to research the subject in detail to understand it more fully, you can find a lot of information with Google and searching here.

For FTA (or FSS) band equipment, there hasn't been a great deal done with bandstacking. There really wasn't a great market for it until recently. Most of us in the FTA hobby don't utilize DN equipment because the FTA signals are not in the DBS band (only a few that DN allows to slip by or which are mandated FREE channels like NASA). Bandstacking may become a valued technology for FTA use in the future.

Another, newer technology that may prove rather wonderful is optical LNBFs. INVACOM is working on just such a technology in recent years. Here, you could essentially have any number of LNBFs and any number of receivers and the cable run could be 1000's of feet between the dish/dishes and the receivers. A neat idea!

RADAR

It should be noted that stacked LNBs are not only for circular DBS... There are Ku-Band and C-Band linear stacked LNBs as well. I think the technology is great, since it basically gives you the advantages of an orthomode feed without the cabling hassles...