CREATE TABLE table_204_270 (id NUMBER, "transmitter" CLOB, "kw" NUMBER, "bbca" NUMBER, "bbcb" NUMBER, "d3&4" NUMBER, "sdn" NUMBER, "arqa" NUMBER, "arqb" NUMBER, "pol." CLOB, "a.g." CLOB)

which transmitter is previous to staithes
SELECT "transmitter" FROM table_204_270 WHERE id = (SELECT id FROM table_204_270 WHERE "transmitter" = 'staithes') - 1
SELECT "transmitter" FROM "table_204_270" WHERE "id" = (SELECT "id" FROM "table_204_270" WHERE "transmitter" = 'staithes') - 1