My son has an HD dish system on site with one unused outlet. Can I
somehow use a splitter on that feed to run my two house receivers?
What kind of splitter do I need? Thanks for any help!

DiSH and DTV hardware is not compatible. You can put a DiSH receiver
at your house, and really good coax, and you might make it. DiSH has
UHF RF remote control, but I don't know how far that works. What is
the distance? We tend to call 100m the outer limits.

You misunderstood. I don't have nor want Dish Network. Both my and my
son's systems are DirecTV but his is HD and mine is not. My question is
if I can connect my receivers to his dish with some kind of splitter,
and if so, what kind will work. I can't make any sense of the online
info so I don't know what to buy. This will be a temporary hookup while
my rooftop hardware is removed for a time during construction.

Ray