we get 54.2 &3 but not 54.1

So we receive the sub channels well but nothing of the primary channel.
Any ideas about correcting this issue?
We also have a pbs channel in lo-v (20.1 rf6 -32 dbm) this channel is 114
degrees of from other towers. Can I add another antenna and can someone recommend one to receive this lo-v signal (22miles away)?