Complex sentence: Here he operated a radio station under the codename "Upsilon" and he was instrumental in dealing a blow to the German battleship "Tirpitz" on 22 September 1943 (Operation Source).
Split into simpler sentences: Here he operated a radio station under the codename "Upsilon". Here, he was instrumental in dealing a blow to the German battleship "Tirpitz" on 22 September 1943 (Operation Source).