Ryf (“Ball End” / “Ball Gun”) radar

(USSR)

Notes: Development of this surface search radar was ordered by the USSR Council Of Ministers as part of the first (1946-1948) post-WWII Three-Year Plan. It was designed by the Kalmykov-Ignatyev bureau. Development was fast and the prototype set was ready on 9 August 1946. The system completed sea trials (aboard the old cruiser Molotov) in the summer of 1948 and was placed into production immediately.

“Ball End” was an I/J-band set with a truncated parabola dish. It had a peak output of 150kW. It could be set for constant search (360 degree rotation), sector search, or locked-on tracking modes. It was used for general search, and also gunnery aboard some ships (it was capable of fall-of-shot calculation by plotting shell splashes from larger-caliber guns). The simple PPI display was ranged out to 25NM but it was only reliable to about 20NM vs. an Iowa class battleship-sized target, 12NM vs. a Gearing class destroyer-sized target, 7NM vs. a surfaced submarine or patrol boat-sized target, and 4NM vs. a low-flying Avenger-sized airplane. It had enough discrimination to detect a submarine periscope at 1NM. Error was +/- 60’ at close ranges and 1% of the total range at longer ranges.

“Ball Gun” was a later refinement with slightly improved performance and a modified antenna.

“Ball End” was exported and remained in worldwide use up until around the turn of the millennium. Confusingly the name ryf (“coral reef” in Russian) was recycled for later unrelated naval electronics.

USERS: USSR, Albania, Algeria, Bulgaria, China, Egypt, Indonesia, Syria, Yemen