In regards to clearance Delivery, it should pick it up, I have tried tuning into clearance and unfortunatley it sticks to noise as such it stops the scan and you'll hear noise. I'm about 6km north of YBBN.
If the feed goes down 2 things probably have happened,
1. I have taken the scanner to the actual airport to do some spotting,
2. the system restarted following updates while I was away and I haven't noticed. Both of these would be quickly fixed, so don't fret if there are any downtimes.
The current antenna is very poor yet I think considering it's capabilitiy it's doing a great job. So the new antenna I'm hoping will vastly improve clarity/range.
however finances don't allow me to currently purchase, so for now it's going to be as good as it gets.