Satellite antennas come in two types times two types for this discussion
Dome and Dish
Single or Dual (And for DircHDTV SWM)
I know of no DOME type that will work with DirecHDTV for RV use (Marine perhaps but that is a different environment) and I do not think anyone is working on one
A dome with DUAL OUTPUT (A dual) can work with multiple receivers on DirecTV (NO HD however)
With dish,A dome works best with one reciver.. SD or HD does not matter but one dome per receiver dos.
DISH type antennas.. There are several "Sub Models" Each Sub model works with one type of service.. if the dish is either DUAL or SWM (Single Wire Multiplex) it works with multiple receivers.
NOTE: Single and dual refer to OUTPUT connections, NOT to the number of lenses or "Hockey Pucks" but to the numbr of outputs.
DircTV uses a SOLO (One lense)
DISHnetwork SD a TWIN (Two)
HD antennas are Triplets (3 Lenses)
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times