MARCONI TRAWLER TRANSMITTER TYPE 517/18

THE ABOVE TRANSMITTER WAS DESIGNED EXCLUSIVELY FOR TRAWLER USE AND COVERED THE BANDS 109 - 200 METRES OR ALTERNATIVELY 120-230 METRES. IT COULD BE USED FOR A.M PHONE AS WELL AS C.W  WORKING. WITH THE ADAPTER UNIT IT COULD HAVE ITS BAND COVERAGE EXTENDED TO COVER 600-800 METRES ( ADAPTER TYPE 518, SHOWN TO THE RIGHT OF THE MAIN SECTION OF THE TRANSMITTER, BUT ONLY CW COULD BE USED ON THE EXTENDED RANGE ) THERE WAS ALSO A 517M TRANSMITTER, WHICH WAS ESSENTIALLY THE SAME AS THE 517, BUT GAVE A HIGHER OUTPUT.