To add to Dutch's reply:
According to the
Winegard site there are three separate Trav'ler models, one for DirecTV, one for Dish and Bell, and one for Shaw. I know that the one for DirecTV can have the dish replaced with one for Dish, but that didn't work in reverse when I got mine (related to the mounting base, I'm told). Looking at the specs the Shaw version is the heaviest, so it might be possible to change out the dish part, though I've found nothing to actually indicate that.
I found a PDF on Winegard's site that (in part) says:
Conversion kits are available for the TRAV?LER antenna. The conversion kits
are compatible with converting the DIRECTV Slimline antenna (SK-3005),
DIRECTV triple LNB (SK-3003), or DIRECTV SWM Slimline antenna
(SK-SWM3) to the DISH TRAV?LER antenna (SK-1000).
It doesn't list any other conversion kits.
Another PDF from Winegard says (in part):
Q. What happens if I switch service providers with my TRAV?LER antenna?
A. Depending on your previous and new service providers, it may be possible to convert your TRAV?LER antenna to be
compatible with your new service provider. The following conversions are possible:
SK-SWM3 to SK-1000, SK-3005 to SK-1000, and SK-1000 to SK-3003.
So that's DirecTV to Dish, DirecTV to Dish and Dish to DirecTV, respectively.
Another part reads:
Q. What satellite service providers and satellites work with each TRAV?LER antennas?
A. TRAV?LER antenna is designed to work with specific providers. The TRAV?LER antennas work with DIRECTV, DISH, Bell
Each TV, and Shaw Direct. The DIRECTV SWM TRAV?LER antenna is compatible with satellites 99?, 101?, and 103? for
DIRECTV SD/HD programming. The DISH/Bell TV TRAV?LER antenna is compatible with satellites 110?, 119?, 129? for
DISH Western Arc SD/HD programming and satellites 82? and 91? for Bell TV SD/HD programming. The Shaw Direct
TRAV?LER antenna is compatible with satellites 107? and 111? for Shaw Direct SD/HD programming.
So compatibility is not only the dish itself, but also what the electronics will find and the LNBs will support.
Apparently this topic got moved while Dutch and I were composing our posts, so the replies initially went to another satellite topic -- confused me for a bit. So I'll delete my posting in other topic.