(a) Any state or other public officer who is required by law to publish any notice, may supplement publication thereof by causing such notice or a concise summary or description thereof to be broadcast at such times and with such frequency determines to be suitable when, in the officer's judgment, the public interest is served thereby.
(b) Notices by political subdivisions of this State, cities, municipal and quasi municipal corporations, special districts and other public agencies shall be made only by stations whose primary broadcast coverage encompasses the county or counties in which the notice is required to be given.