user: Question: When 1180 AM is the frequency how many call signs are there?
Columns: ['Call sign', 'Frequency', 'City of License', 'Licensee', 'Format']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['WADK', '1540 AM', 'Newport', 'Astro Tele-Communications Corp.', 'News/Talk']
SQL:

assistant: SELECT COUNT("Call sign") FROM "Table" WHERE "Frequency" = '1180 AM';