After comments from several users we have decided to remove all advertising from the website for the time being.
We are still considering working with radio related businesses that would benefit from discrete advertising or sponsorship.
We would like to try and move away from the free hosting we are currently using, although it works well most of the time we do hit bandwidth limits which can be frustrating for the user. As a result we are trialling a couple of discrete adverts from Amazon with a view to using the money raised to pay for hosting fees.
Amazon affiliate ads didn't really work for us, limited variety of adverts and poor return for the given impressions and clicks.
We are now trying Google ads and appreciate your feedback.