I believe I have it. I found this link today :
DISH Network Dishes : LNB : 500
After a day of research it also appears that these facts are true:
- In the "double headed LNB 2-satellite receiver" category this is a unique multi-single-stage LNB that people call "Legacy". It is the oldest made and must have a combiner device named SW 21 (or other model if more than 2) to connect the two twin LNBs into a single coax that will enter the home.
- In the "square headed LNB 2 satellite receiver" category there can be 3 different types of LNBs
- What people call "Legacy" is a unit that has simply "Dish Network" stamped on the back (no ink), and the plastic goggles that face the dish appear as an oval, like a welder's goggles
- What people call "Dish Pro" is a unit that is very similar and has in black ink "DP" stamped on the back and the two circular plastic receiver covers appear detached, resembling a pair of binoculars
- What people call "Dish Pro Plus" is a unit that is very similar and has in black ink "DP Plus" stamped on the back and the plastic receiver covers appear detached, resembling a pair of binoculars
Note that some might say this is overkill but there are a lot of these units apparently that have been sun bleached and/or painted over. Regardless I hope this helps others in my previous situation.
Second subject and my catalyst this time for landing here; I am assuming at this point that a splitter or the device part number 123254 that works to split a signal for a 2 channel receiver can only work with a head (LNB) marked "DP Plus".
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Caveats:
I discovered several other things during my research and testing this week. Now I have re-aligned several dishes during my lifetime, normally post-windstorm and ad-hock but finally gave up recently after typically spending 8 or more hours on this task when an antenna swap-out is involved. I recently purchased a small meter to detect the signal, hoping this would help. I thought I was home free but when I used it a few times to upgrade an antenna, I never could figure out why the inline meter needle was off and on, working sometimes and sometimes not. Apparently (speaking as only someone with click-experience), there is only a signal in the line available to drive an inline meter when the receiver at the end knows this is the right "switch", so you may be doubly frustrated in lining up an antenna because if the antenna is a different model than the receiver last disconnected, it has been my experience that there will be no signal on the meter, even if you are dead-on the satellites. I also discovered that the switch-type seems to be undetectable by the receiver unless the antenna is exactly aligned and only a near perfect alignment will allow the receiver to learn what kind of switch it has. A catch 22. So what I have done when helping a friend or neighbor swap out for a different antenna model number, is I have to take a small TV and a receiver on the roof, as well as having a meter in line. First I align the dish with the compass, then keep running the check switch routine over while tweaking the antenna, doing this over and over until I get the switch recognized. Only then can I seem to utilize the meter to fine tune the signal. Of course by this point I really don't need the meter because I am the idiot sitting on the roof watching TV ;-)
Finally and to expand on that, the whole concept of a "switch" (opposed to splitter or combiner) seems kind of archaic even by "legacy" standards; that is, why anything would have to switch off and on, and particularly today when you can have multiple receivers sharing the same antenna. Perhaps the "legacy" technology could not handle the concept of dual signals passing down the line, the hardware to handle it was significantly more expense and perhaps today it is something that has remained due to backward compatibility. My understanding of it now - "strange but workable" ;-).