I'm having DVB-t reception issues. I can't get any of the channels on the TV1 and TV2 MUX. I do get TV3,4 and that MUX perfectly.

I have a UHF aerial I installed new a year ago, but I used existing cabling that is looking a little worse for the ware. It's probably 10 years old and a good length of it is exposed to the elements. Also it's RG59, not RG6. It plugs directly into my HTPC with no splitting. 

I was thinking of putting new cabling in but, when I first installed everything last year I was getting TV1 and TV2 etc, in fact everything was fine except but Prime was a little iffy. I live in Mt Maunganui and have the aerial pointed to Te Aroha. 

In an effort to try and fix my prime reception, I tried adjusting the aerial and pointing towards the Kopukairu transmitter. No joy, I only got TV3, 4 etc. 

So I realigned the aerial with Te Aroha but I still only get TV3, 4 and the channels on that MUX. Their reception is perfect. I have tried everything, but can't get TV1,2 or any channels on the MUX to work. 

Could the old cabling from the aerial to the HTPC be the issue? Would it allow perfect reception of one group of channels  but not virtually nothing for the others? I would just change it to new RG6 but the I'm living in a rental and don't want to spend money upgrading the cabling if it's not going to fix the issue.

Any other ideas? I am definitely pointing directly at the Te Aroha transmitter. I've got good line of sight and have used google maps and plotting software and a compass to make sure its right on target.