There was SD radar, which was Air Search, and in RFB, that raises and lowers. The only way to turn it off is to submerge the boat. You do not have a "radar" screen for it however, only the NavMap will display its "contacts". The "screens" you are looking at with the on/off, range, etc. swiches are for the "A" scope and PPI screens of the SJ radar, which is the surface radar. The SH4 devs had a plan to implement a cover, similar to what SH1 had done, for those two screens, but never got to it before the game was released. One of several "features" never realized in the game - FM sonar being another. You will not have functioning SJ surface search radar until after the middle of 1942 in any phase of the game. I cannot remember the exact dates in RFB or Stock either... but that's why your "switches" won't work.
