With funding for public broadcasting under fire in Canada, you would think that the CBC would take all the help and support it could find. But a new organization agitating on behalf of the $900-million-a-year public network is being regarded with some suspicion by CBC higher-ups. Our Public Airwaves, a pro-CBC lobbying group which sprang into existence last summer, has so far done nothing to which the company could object. But OPA is a creation of the two unions representing CBC workers, and at a time when relations between management and labor have not exactly been cozy, the CBC brass are not openly embracing the group.