I have the VR-509, as well (no, it's not the Sovereign line). The supplied RC-R0913 remote went dead some time ago... but it was pretty obvious (the LCD fails to display anything).

I do know, when it was working, for RF I definitely needed the RF antenna... no matter how close I was... it was simply required. The RC-R0913 didn't have RF vs. IR mode. Both were just "always on"... and whatever the receiver received was fine with it. I don't know for sure if the RC-R0811 is the same way... but I'd wager it is. So, jtcrom is correct... even without an antenna, the remote should still be able to control the receiver under IR. If it doesn't, either the remote is broken, or the IR receiving sensor is broken (which could be something as simple as the protective window being severely scratched).

Does anybody know of an after-market RF remote that would work with the 509? I could replace the RC-R0913... but, as a remote, it stunk anyway. I'd hate to have to buy another one.