I have Satellite, and the channel for me atleast is 379. I think it is elsewhere to.
to be honest, i don't watch the show enough to know the exact times, and it appears to have changed on me! it was on at 9 this morning with trains of PRR's western line. Its usually on saturday mornings, and around 6 in the afterrnoon on some week days, but i'll have to check.
the other thing i noticed is that its on some days and times, but not consistently. if your cable has a guide, you could look through there once you find RFD.