Can't you make one out of a large paperclip, a plastic bead, and a used connector? -
. . . or maybe a length of music-wire from a hobby-shop.
Is lack of that little antenna really a concern?
edit: sorry, don't mean to be rude.
Just seems like something easy enough to fashion if it's missing.
And I think DishStore may even sell them...
It's easy enough to make one out of a piece of coax if the jack is an F connector like most are.
I have a DN 222 receiver located in the bedroom, and my wife sometimes watches the second tuner in the living room. She was having some trouble with the remote not responding properly. I used a piece of coax from the UHF antenna jack and ran it into the basement and tacked it to a floor joist at a point under her chair. I cut the jacket and braid and left a length of center conductor that was close to the length of the little antenna...no more problem...