i use a $20 FM transmitter radio attachment for my phone (draws power from my phone and headphones act as the antenna) and am able to listen to the track side radio broadcast. otherwise use a radio app on your phone but for there will be data charges associated with that. or go old school and bring a portable radio.
actually im lucky in Canada as my provider allows me to use data anywhere in Canada without incurring additional roaming charges so i can use the live timing on the website on the cheap.
last race i went to (2 years ago) i used my phone (main phone) as a mobile hotspot and connected an old phone of mine to that network and ran a live mobile stream off of it which gave me access to the TV commentary without drawing too much power from my main phone.
even allowed some of my out of country neighbours in the grandstand to connect to my network so they could follow the live timing/radio broadcast on their own phones. they rewarded me with beer
