Tvheadend

I've setup TVHeadend on my Raspberry Pi. I know my OTA tuner works on the pi (i've been able to watch some channels) but i can't seem to automatically scan for and add muxes. The predefined list only got me like 6 channels while i should get about 14. I get 14 when i use nextpvr on my desktop machine. I'm expecting to click a button that automagically scans the network and add muxes.

I assume there is a way to not use a predefined list and just scan for channels. The "force scan" on the network tab seems to do nothing if no muxes exist.I click force scan and i see nothing happen and nothing shows up in the log window below

i'm running HTS Tvheadend 4.2.4-dmo1~bpo9+1~rpt1.
Auvitek AU8522 QAM/8VSB Frontend #0 : ATSC-T #0

I'm in ottawa canada

Any ideas?

Thanks