Also, primary radar only exists around Capital City Primary CTR's.
Good to see you're recognising Cairns as the capital of FNQ.
Ask for a clearance on the appropriate frequency at 10 miles prior to the boundry.
If you're inbound to an Approach controlled aerodrome, I'd suggest you call at least 20 minutes prior to ETA or 5 minutes prior to entering CTA whichever is the earliest. This simply allows us to sequence your arrival in a timely and equitable manner. And it doesn't cost a cent extra.
If you call 10nm prior to the CTZ, and we have a solid sequence for the next X minutes, then expect a delay.